Answer:
Endothermic - Ice cubes absorbing the heat around them to melt into water.
Exothermic - Candle burning giving off heat into the atmosphere.
Help me please.
How do animals see their pray without light?
Answer:Many nocturnal animals have a mirror-like layer, called the tapetum, behind the retina, which helps them make the most of small amounts of light.
Explanation:
Which of the following statements about the valence electrons is false?
a.Valence electrons are involved in bonding.
b. Valence electrons are found in the outermost energy level.
c. Number of valence electrons determines whether atom forms a covalent or ionic bond.
d. Valence electrons are found in the nucleus.
Answer:
d. Valence electrons are found in the nucleus.
Explanation:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom.
The other 3 statements are correct.
Cell Membrane Transport
List 5 observations when you open the blue and green gated channels:
Section 2
After listing your observation, click “reset all” and do the same process again, following the instructions listed above. Answer the following questions below.
1.) Open the green gated channel and observe. What did you observe when you open the green gated channel?
2.) Based on your observations, what type of solution have you observed? Is it ‘hypertonic’, ‘hypotonic’ or ‘isotonic’? Explain
3.) Open the blue gated channel. Observe on what will happen when you open the blue gated channel. What have you observed?
4.) What type of solution have you observed? Is it ‘hypertonic’, ‘hypotonic’ or ‘isotonic’? Explain.
5.) Slow down the animation. What did you observed on the motion of the green circles and blue diamonds?
A type of fossil fuel,known as Tar stands.
what is fossil fuel?A fossil fuel is a hydrocarbon-containing material formed naturally in to the Earth's crust from to the remains of dead plants and animals and birds that is the extracted and burned as thr a fuel. The main fossil fuels are mainly coal, oil, and natural gas.
Tar sands are a combination of clay, sand, water and bitumen, which is a heavy hydrocarbon. Like the kerogen in oil shale, tar sands' bitumen can be upgraded to synthetic crude oil.
So answer is tar sands.
These include tar sands – deposits of moist sand and it is clay with 1-2 percent bitumen (thick and heavy are petroleum rich in the carbon and poor in the hydrogen). These are the removed by strip mining in the (see section below on coal)
To know more about fossile fuel click-
https://brainly.com/question/79954
#SPJ1
Use these two constants for the question that follows:
e = 1.6 × 10−19 C
k = 8.99 × 109 N m2/C2
Two positive charges are 10−16 m away from each other. Using Coulomb's law, what is the strength of the force of attraction between these two particles?
144 N
160 N
230 N
287 N
The force of repulsion between the positive charges has a magnitude of 230 N. Option B
What is the Coulomb's law?We know that the Coulomb's law deals with the way that two charges are able to interact. The interaction between the two charges could be such that the charges are attracted to each other or the charges are repelled from each other.
The forces of attraction and repulsion are the bases of the Coulomb's law. According to the Coulomb's law, the forces of attraction or repulsion between two charges would depend on the product of the magnitudes of the charges and inversely proportional to the distance that separates the charges.
Hence;
F = K[tex]q_{1}[/tex][tex]q_{2}[/tex]/r^2
F = Coulomb's force
[tex]q_{1}[/tex]and [tex]q_{2}[/tex] = magnitude of the charges
r = distance of separation
Then;
F = 8.99 × 10^9 * (1.6 × 10^−19)^2/(1 * 10^-16)^2
F = 2.3 * 10^3 N
Learn more about Coulomb's law:https://brainly.com/question/506926
#SPJ1
Calculate the value of the reaction quotient, Q, for the galvanic cell expressed using shorthand notation below.Use the balanced chemical equation that has the smallest, whole number stoichiometric coefficients.Zn(s) | Zn^2+(aq, 0.0100 M) || Ag+(aq, 1.25 M) | Ag(s)
The value of the reaction quotient, Q, for the galvanic cell for the galvanic cell expressed using shorthand notation is 64×10 ^−3
Zn(s)+2Ag (1.25M)Zn2+ (0.01M)+2Ag in a cell (s).
Q= [Zn ^2+ ]/[Ag ^⊕ ]
Q= 0.01 / (1.25)^2
Q= 64×10 ^−3
What is galvanic cell?An electrochemical cell called a galvanic cell or voltaic cell, respectively named after the scientists Luigi Galvani and Alessandro Volta, produces an electric current by spontaneous oxidation-reduction reactions.Voltaic or galvanic cells are electrochemical devices that use spontaneous oxidation-reduction events to generate electricity.A galvanic cell is an electrochemical cell that uses a chemical process to generate electricity. The electrolytic cell propagates a chemical process using an electric current. Chemical energy is transformed into electrical energy in this cell. Electrical energy is transformed into chemical energy.For more information on galvanic cell kindly visit to
https://brainly.com/question/13031093
#SPJ4
Mechanism and products
There are so many types of chemical reaction reaction like combination reaction, double displacement reaction, nucleophilic substitution reaction etc. Therefore, the reaction is nucleophilic substitution reaction. The product formed is 1-bromo-2-methyl-2-phenylethane.
What is nucleophilic substitution reaction?One nucleophile substitutes another in a family of organic reactions known as nucleophilic substitution reactions.
The characteristics of SN1 mechanism:
SN1 stands for nucleophilic substitution reaction.
Leaving group, a nucleophile, electrophile and a solvent are present
Because a link is being severed, the first step is the most laborious.
In the given reaction, firstly H⁺ will attack OH to make good leaving group, then generation of carbocation will take place. Thereafter Br⁻ will attack the carbocation forming C-Br bond. The product formed is 1-bromo-2-methyl-2-phenylethane.
Therefore, the reaction is nucleophilic substitution reaction. The product formed is 1-bromo-2-methyl-2-phenylethane.
Learn more about the chemical reactions, here:
https://brainly.com/question/28097754
#SPJ1
which of the following is not one of the three types of liquidity in terms of meeting cash needs in production cycles?
Meeting cycle due dates is not one of the three types of liquidity in terms of meeting cash needs in production cycles
Describe the production cycle.The process of turning raw resources into completed goods is referred to as the manufacturing cycle. The cycle consists of numerous independent parts, including product design, scheduling of production, manufacturing tasks, & a cost accounting feedback process. The production cycle of a business reveals how well it can turn assets into earnings, inventories into goods, & supply - chain into cash flow.
Describe the four fundamental steps in the production cycle.The product design, planning and scheduling, production operations, and cost accounting are the four fundamental steps in the production cycle.
To know more about production cycle visit :
https://brainly.com/question/13167295
#SPJ4
What is the meaning of "implicit"?
A) Found in a text
B) Implied by the text
C) Stated directly
D) Stated from evidence
yoo anyone know this one>
100 POINTS HELP PICTURE BELOW
Answer:
there is no picture. please add it so i can see :)
Explanation:
a proposed method of producing methanol how much heat must be added or removed from the whole system
A proposed method of producing methanol 5.58J heat must be added or removed from the whole system.
What is methanol ?
Having the chemical formula CH3OH, methanol is a liquid (often abbreviated MeOH). It has no color and is toxic, combustible, volatile, and unstable. The main building blocks for the synthesis of methanol are carbon monoxide and hydrogen, and it is produced by destructively distilling wood.
What is heat ?
Heat is the result of the movement of kinetic energy from one substance or item to another, or from an energy source to a substance or object. Radiation, conduction, and convection are three different ways that this energy might be transferred.
Therefore, a proposed method of producing methanol 5.58J heat must be added or removed from the whole system.
Learn more about methanol from the given link.
https://brainly.com/question/17459581
#SPJ4
find the molarity and malality of 37.0wt% HCL given that the density of the reagent is 1.19g/ml
1) Let us assume 100.0 grams of solution. Therefore:
37 g is HCI
63 g is H2O
2) Calculate molality:
moles HCI = 37 g/ 36.5 g / mol = 1.014 mol
kg of water = 0.063 kg
molality = 1.014 mol / 0.063 kg = 16.09 molal
1) Determine moles of HCI in 100.0 g of 37% solution:
37 g of this solution is HCI
37 g / 36.5 g / mol = 1.014 mol
2) Determine volume of 100.0 g of solution:
density = mass / volume
1.19 g / mL = 100g / x
x = 84.03 mL
3) Determine molarity:
1.014 mol / 0.084 L = 12.07 M
learn more about Molarity at
https://brainly.com/question/17138838
#SPJ1
Water, H20 is a molecule made of oxygen and hydrogen. The bonds that hold water molecules together are due to shared electrons and known as ________bonds. In contrast, the bonds that hold NaCl molecule together are_______bonds, arising from charge difference between the atoms.
Answer:
Water, H20 is a molecule made of oxygen and hydrogen. The bonds that hold water molecules together are due to shared electrons and known as Covalent bonds. In contrast, the bonds that hold NaCl molecule together are Ionic bonds, arising from charge difference between the atoms
Calculate the enthalpy of solution for calcium chloride (110.98 g/mol) using the following data: When 37.73
g of CaCl₂ is dissolved in 240.00 g of water, the temperature of the solution increases by 24.25°C. Assume the
specific heat of the solution is 4.18 J/(g. °C).
CaCl(s) → Ca²+ (aq) + 2 Cl(aq)
AH=? kJ/mol
The enthalpy of the reaction is then obtained as 71.5 kJ/mol.
What is the enthalpy of the solution?We know that the enthalpy of the reaction has to do with the amount of heat that is absorbed or lost in the reaction. In this case, we can see that our task is to obtain the enthalpy of the dissolution reaction.
Number of moles of the calcium chloride = 37.73 g/110.98 g/mol
= 0.34 moles
Mass of the water = 240.00 g
Heat gained by the water = mcdT
m = mass of the water
c = heat capacity of the water
dT = Temperature change
Then;
H = 240.00 * 4.18 * 24.25
H = 24.3 kJ
Enthalpy of the reaction = -( 24.3 kJ)/0.34 moles
= 71.5 kJ/mol
Learn more about enthalpy:https://brainly.com/question/3393755
#SPJ1
What is the volume of oxygen gas at stp from thr decompositon of 10.8g of mercuric oxie (216.59g/mol)
The volume of oxygen gas from mercuric oxide at STP from ideal gas equation is 123.54 liters.
What is ideal gas equation?The ideal gas equation is a equation which is applicable in a hypothetical state of an ideal gas.It is a combination of Boyle's law, Charle's law,Avogadro's law and Gay-Lussac's law . It is given as, PV=nRT where R= gas constant whose value is 8.314.The law has several limitations.
Substituting the given values in ideal gas equation, V=mass×RT/molar mass×P=10.38×8.314×298/216.59×1=123.54 L.
Thus, the volume of oxygen gas at STP is 123.54 L.
Learn more about ideal gas equation,here:
https://brainly.com/question/28837405
#SPJ1
(a) the complex ion [ni (cn) 4 ]^ 2- is diamagnetic. explain using crystal field theory whether the structure of this complex ion is octahedral, square planar, or tetrahedral. .
−C≡N is the classic low spin ligand.
What is Ligand?
The Latin root of the term "ligand" means "to tie or bind." Anions, cations, and neutral substances can all function as ligands. Lewis bases are ligands that provide electron pairs, whereas Lewis acids are central metal atoms (electron pair acceptor). Covalent and ionic bonds are two different types of bonding that can exist between a metal and its ligand.
On rare occasions, ligands can be electron-pair acceptors and cations (NO+, N2H5+). Examples of neutral ligands include NH3, H2O, NO, and CO, whereas anionic ligands include F-, Cl-, Br-, I-, S2-, CN-, NCS-, and OH-.
Learn more about Ligand from given link
https://brainly.com/question/1869211
#SPJ4
When X rays of wavelength 0.090 nm are diffracted by a metallic crystal, the angle of first-order diffraction (n = 1) is measured to be 15.2. What is the distance (in pm) between the layers of atom responsible for the diffraction?
When X rays of wavelength 0.090 nm are diffracted by a metallic crystal, the angle of first-order diffraction (n = 1) is measured to be 15.2. The distance between layers in an NaCl crystal is 282pm.
What is wavelength?
A waveform signal that is carried in space or down a wire has a wavelength, which is the separation between two identical places (adjacent crests) in the consecutive cycles. This length is typically defined in wireless systems in metres (m), centimetres (cm), or millimetres (mm) (mm).
The wavelength, which will also apply to troughs, is the separation between two wave crests. The frequency is measured in cycles per second (Hz), which is the quantity of vibrations that cross a specific area in a second (Hertz).
To know more about wavelength, click here- brainly.com/question/10728818
#SPJ1
When X rays of wavelength 0.090 nm are diffracted by a metallic crystal, the angle of first-order diffraction (n = 1) is measured to be 15.2. The distance between layers in an NaCl crystal is 282pm.
What is wavelength?Wavelength is a measure of the distance between two consecutive peaks or troughs in a wave. It is usually represented by the Greek letter lambda (λ) and is measured in the SI unit of meters. Wavelength is an important parameter in many fields, including physics, acoustics, optics, and astronomy. In physics, the wavelength of a wave is related to its frequency, period, and energy. In optics, it is used to describe the properties of light, and in astronomy it is used to describe the properties of radio waves and other forms of electromagnetic radiation. Wavelength is also used to calculate the angular size of an object and its distance from Earth. Wavelength is an important concept in understanding the behavior of light and sound, and their interactions with matter.
To know more about wavelength, click here- brainly.com/question/10728818
#SPJ1
4) How many moles of a gas occupy 347.8 mL, at 4.369 x 10-1 atm and 25.00 C?
The number of moles occupied by a gas at 347.8 mL is 6.21 × 10-³moles.
How to calculate moles?The number of moles occupied by a gas can be calculated using the ideal gas equation formula as follows:
PV = nRT
Where;
P = pressureV = volume n = number of molesR = gas law constantT = temperatureAccording to this question, the following parameters are given:
P = 0.4369atmV = 0.3478LT = 25°C = 298K0.4369 × 0.3478 = n × 0.0821 × 298
0.1519 = 24.47n
n = 6.21 × 10-³moles
Therefore, 6.21 × 10-³moles is the number of moles of the gas.
Learn more about moles at: https://brainly.com/question/12513822
#SPJ1
Select the correct answer.
The benefits of a Supervised Agriculture, Experience include all the following EXCEPT
О А.
OB.
O c.
O D.
a guaranteed salary.
getting hands-on experience in the field.
developing skills those in agriscience need.
the opportunity to explore a potential career.
A. guaranteed salary.
Supervised Agricultural Experience (SAE)
A supervised agricultural experience (SAE) is an organized opportunity for experiential and work-based learning outside of the classroom in a setting other than a school setting that takes place outside of regular school hours in order to enhance a student's industry.
A few examples are cultivating and selling livestock or crops, making and selling farm machinery, purchasing and reselling feed, seeds, and fertilizer, running a pet-care business, or programming and installing computer hardware in tractors.
Programs for supervised agricultural experience fall into one of four categories: exploratory, entrepreneurial, placement, or research/experimentation. The SAE for each student is determined by their interests and the opportunities that are accessible.
To learn more about Supervised Agricultural Experience (SAE)
https://brainly.com/question/14840028
#SPJ1
PLEASE HELP!!
Which physical adaptations increase an organism's chances of physically defending itself?
(Select all that apply.)
O the venom of a snake
the horns of cattle
O the wax-producing glands of bees
O the bright plumage of birds
The venom of a snake, the horns of cattle, the wax-producing glands of bees, and the bright plumage of birds all are physical adaptations that increase an organism's chances of physically defending itself.
What are physical adaptations?Physical adaptations do develop over many generations. The shape of a bird's beak, the thickness or thinness of the fur, and the shape of the nose or ears are examples of physical adaptations.
Adaptation can be described as a characteristic that provides defense for an animal to survive in its habitat. All animals should be able to get food and water, protect themselves from harm, and climate, and reproduce young species.
Horns and antlers can be used to protect themselves, fight for territory, or to attract a mate. The leaves are coated in the wax which reduces water loss and stops the plant from drying out. Some butterflies and birds have bright, vivid colors that provide them stand out from their surroundings and serve as a warning to predators.
Learn more about physical adaptations, here:
https://brainly.com/question/27747697
#SPJ1
how many moles of hydrogen gas are produced from the reaction of 4.75 moles of zinc and an excess amount of hydrochloric acid
In the given question, the moles of hydrogen that can be obtained from the reaction is 4.75 moles.
The reaction of zinc with hydrochloric acid can be written as:
Zn + 2HCl ⇒ ZnCl₂ + H₂
This reaction is a displacement reaction, in which zinc displaces hydrogen from hydrochloric acid. Hydrogen is released from HCl and hydrogen gas appears at the end of the reaction.
It can be seen that 1 mole of zinc combines with 2 moles of HCl to produce 1 mole of hydrogen gas. If 4.75 moles of zinc is combined with an excess amount of HCl, then it will produce 4.75 moles of H₂.
To know more about the calculation of moles, visit: https://brainly.com/question/21182981
#SPJ1
Oxygen and chlorine gas are mixed in a container with partial pressures of 3040 mmHg and
1.63 atm, respectively.
What is the TOTAL pressure inside the container in atm? *Don't forget to convert: 760mmHg
= 1atm*
Answer:5.63 atm
Explanation: Dalton's Law states that total pressure of a mixture of gasses is equal to the sum of partial pressure of each gas.
[tex]P_{tot} = P_{1} +P_{2}+ P_{3}...[/tex]
We are given pressure O2 and pressure Cl2.
Step 1: First, convert 3040mmHg to atm by dividing by 760.
[tex]\frac{3040mmHg}{760atm} = 4 atm[/tex]
Step 2: Plug your numbers into the equation
[tex]P_{tot} = P_{O2} +P_{Cl2}[/tex]
[tex]P_{tot} = 4atm + 1.63 atm = 5.63 atm[/tex]
How many grams is equal to 1.11 moles of NaCl?
Answer:
64.38g
Explanation:
Mass no. of Na is 23 and mass no. of Cl atom is 35. Total is 58. 1 mole of NaCl is 58g. 1.11 moles of NaCl is 1.11x58=64.38g.
which of the following expands most when the temperature is increased? equal volumes ofquestion 14 options:iron.helium.wood.ice water.
Helium expands most when the temperature is increased.
For a given rise in temperature, gasses expand much more and faster than liquids. This is due to the fact that gasses have more interatomic or intermolecular space than liquids. Among the given, helium is a gas while the rest are liquids: Helium expands more than the rest.
What is temperature?
Temperature is a physical quantity that quantitatively expresses the sensations of hotness and coldness. The temperature is measured with a thermometer. Thermometers are calibrated in different temperature scales, which historically relied on different reference points and thermometric substances for definition.The Celsius scale (°C) is used for temperature measurements. It is an empirical scale that has evolved historically, leading to its zero point of 0 °C being defined as the freezing point of water and 100 °C as the boiling point of water.To know more about temperature, click the link given below:
https://brainly.com/question/23411503
#SPJ4
Scientists used radioactive hydrogen to make water. They grew plants using radioactive water. What happened to the radioactive hydrogen during photosynthesis? (1 point)
(A) It was recycled into water.
(B) It was recycled into light.
(C)It was recycled into glucose.
(D)It was recycled into hydrogen gas.
Radioactive hydrogen during photosynthesis It was recycled into glucose .The correct "option is C"
What is photosynthesis ?Photosynthesis is the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.
Therefore during this process hydrogen is combined with carbon dioxide to make glucose.
Learn more about photosynthesis here: brainly.com/question/26568636
#SPJ1
1. The pH of soda is generally around 3, while the pH of drinking water is generally around 7. A student comparing the two beverages concludes that soda is generally 10,000 more acidic than water. In three to four sentences, explain if her conclusion is correct or incorrect and why.
2. If a balloon is kept at a constant temperature, what pressure change would need to occur for the volume to increase to three times the size? Explain your answer.
Answer:
Here you go
Explanation:
1. No, her conclusion is incorrect. pH is a logarithmic scale, which means that a difference of 1 pH unit corresponds to a 10-fold difference in acidity. Therefore, a difference of 3 pH units corresponds to a 1000-fold difference in acidity, not 10,000. So soda is generally 1000 times more acidic than water.
2.The pressure of the balloon would need to decrease in order for the volume to increase to three times the size. This is due to the fact that air inside the balloon is a gas, and its volume is inversely proportional to the pressure of the gas. Therefore, a decrease in pressure would result in an increase in volume.
Which element, represented by X, reacts with chlorine to produce the compound XCl2?
Aluminum
Sodium
Calcium
Argon
Answer:
C.) Calcium
Explanation:
Because none of the answer choices are nonmetals, we can safely assume this compound is not covalent. This means that the atoms involved in this molecule were ions before they bonded.
Chlorine, located in the 17th column, typically ionizes to become the anion Cl⁻. This anion has a negative charge of -1. The subscript indicates that there are 2 chorine ions in the compound, increasing the overall negative charge to -2 (2 x -1 = -2).
Since ionic compounds are neutral, the correct answer choice is the atom that ionizes to form a cation that can make the overall charge of the compound 0. As such, the cation needs to have a positive charge of +2 (+2 + (-2) = 0).
Aluminum = Al³⁺
Sodium = Na⁺
Calcium = Ca²⁺
Argon = does not typically ionize
Therefore, calcium must be the unknown element (X), making the compound CaCl₂.
the vapor pressure of liquid pentane, , is 100. mm hg at 260. k. a 0.206 g sample of liquid is placed in a closed, evacuated 370. ml container at a temperature of 260. k.
50.5 * 104 grams of the liquid sample are still present in the container at a temperature of 260 K, per the provided data.
What does vapor pressure mean?The equilibrium pressure between molecules moving from a liquid into a gaseous phase & molecules moving from a gaseous phase into a liquid phase in a closed container is known as the vapour pressure of a liquid.
Briefing :Pentane's liquid vapor pressure equals 100 mmHg or 13.33 KPa.
T = 260 K, the temperature
Container volume = 370 mL = 0.00037 m3mol
moles of liquid pentane = n
universal gas constant = R = 8.314 J/(mol·K)
Thus From the ideal gas equation PV = nRT →
Thus plugging in the values in the above equation we have
n = = 2.16×10⁻³ moles = 2.28*10³ moles
Hence the number of moles in 0.206 g sample of liquid pentane C₅H₁₂ with molar mass = 72.15 g/mol = 0.206/72.15 = 2.86*10⁻³ moles
Hence the number of moles present in the sample placed in the closed evacuated container = 2.86*10⁻³ moles
However number of moles to completely evaporate at 100 mmHg and 260 K is 2.16×10⁻³ moles hence, 2.86×10⁻³ moles - 2.16×10⁻³ moles, or 0.7 ×10⁻⁴ moles will be left in the container
converting the value in moles to mass we have number of moles, n = mass/(molar mass)
Therefore the mass = number of moles × molar mass = 0.7×10⁻⁴ * 72.15 = 50.5 * 10⁻∧4 grams left in the container
The liquid pentane C5H12 vapor pressure, or 100 mm Hg, will be the pressure inside the container at equilibrium.
To know more about vapor pressure visit :
https://brainly.com/question/11864750
#SPJ4
10. What subatomic particle (proton, neutron, or electron) is responsible for determining the identity of an atom
Answer:
proton
Explanation:
Atoms are composed of a nucleus, containing protons and neutrons, surrounded by a cloud of electrons. The number of protons in the nucleus determines the identity of the atom
A pure substance does not conduct electricity in the solid state but it does dissolve in water and the resulting solution conducts electricity. The substance has a fairly high
melting point. The substance is most likely to be what type of compound?
An ionic compound
A crystalline compound
A covalent compound
A metallic compound
Please help I need this by tomorrow morning!!!!
Are the following chemical reactions balanced? explain why or why not.