A chemist needs to know the mass of a sample of to significant digits. He puts the sample on a digital scale. This is what the scale shows:
0
0
0
7
6
.
3
g
If this measurement is precise enough for the chemist, round it to significant digits.
Otherwise, press the "No solution" button.

Answers

Answer 1
76.3 g aka 76 g
In type of scientific measurement, the precision of the measurement is expressed in the significant digits of that measurement. It also used to express measurement to the required degree of accuracy.
Significant digits include every digit except the leading zero(s).
And if the number after the required significant digits is not up to 5, it is rounded down and the required significant digits is written as is. If the number after the required significant digits is at least 5, it is rounded up, and the last number on the significant digits requirement is increased by a factor of 1.

Related Questions

Balance the chemical equation
C2H6+O2 = CO2 +H2O

Answers

c26886
........................

Pls someone help rn!! Pls pls

Answers

Answer:

A. Mass = 61kg, weight on moon = 97.8N

Explanation:

To calculate the weight (force) from Mass of a body, the following formula is used:

W = mg

Where;

W = weight (Newtons)

m = mass (kg)

g = acceleration due to gravity (9.8m/s²)

According to this question, a scale shows that I weigh 600N on Earth, the mass on Earth can be calculated thus:

Using W = mg

m = W/g

m = 600/9.8

m = 61.2

m = 61kg

However, this mass on Earth will weigh differently on the Moon because gravity in the moon is 1.6 N/kg. The weight of the 61kg on the Moon is:

W(moon) = mass × gravity

W = 61 × 1.6

W = 97.6 N

Therefore, Mass = 61kg, weight on moon = 97.8N

Cell Walls are found in Prokaryotes and Plant cells. True O False​

Answers

Answer:

i think true

Explanation:

lemme know if right if not sorry :))

The answer is true. Cell walls are found in both. :)

what does the word interact

Lift

Fly

Discuss

Work with

Answers

Answer:

The answer would be work with.

Explanation:

Because, if we know what the word interact means then we can look for a word similar to interact. hope this makes sense <3.

why blood is separated into different parts​

Answers

Answer:

Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood. The resulting components are: a clear solution of blood plasma in the upper phase (which can be separated into its own fractions, see Blood plasma fractionation),

Answer: Centrifugal force is used to separate the components of blood – red blood cells, platelets and plasma – from each other. ... The red blood cells precipitate to the bottom of the bag, with the platelets above them, then the white blood cells and the plasma at the very top. Also because Each part of the blood has a different function. Separating the blood into parts lets patients get only the specific part or parts of the blood that they need. So a whole blood donation can be used for several patients.

Hope this helps have a awesome day/nigh❤️✨t

Explanation:

1. At an environmental testing lab, a lab technician calculated the known concentration of the calibrating solution three times too high. How will this affect the results of the samples run using this calibration solution

Answers

Answer:

The deviation in the results will be too large when compared with the actual result

Explanation:

The effect this will have on the results of the samples run using this Calibration solution is that the deviation in the results will be too large when compared with the actual result that was supposed to be obtained. and this will also lead to wrong analysis by the technician .

This will cause a result that is very different from the actual result, which will lead to errors in the analysis.

We can arrive at this answer because:

A laboratory test must be done accurately and all calibrations must follow the test protocol.Changing the calibration will cause inaccurate and incorrect results, which differ from the actual result.This will promote an analysis that is unreal, false, and far from true, which will leave the entire test inaccurate.

As we can see from the question above, the lab technician used a much higher calibration than what was recommended in the lab. This will lead to inaccurate and incorrect results.

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molar mass of Mg(CO3)

Answers

Answer:

[tex]\boxed {\boxed {\sf 84.313 \ g/mol}}[/tex]

Explanation:

The molar mass is the mass per mole of an element or substance. The values for atomic mass on the Periodic Table are used as the molar mass. Look up the molar masses for the elements in the formula.

Mg: 24.305 g/molC: 12.011 g/molO: 15.999 g/mol

Analyze the formula. Magnesium and carbon have no subscript, so there is only one atom of each. Oxygen has a subscript of 3, so there are 3 atoms and the mass has to be multiplied by 3.

MgCO₃= 24.305 + 12.011+ 3(15.999) MgCO₃= 24.305+12.011+47.997=84.313 g/mol

The molar mass of magnesium carbonate is 84.313 grams per mole.

Suppose you want to make an acetic acid/acetate buffer to a pH of 5.00 using 10.0 mL of 1.00 M acetic acid solution. How many milliliters of 1.00 M sodium acetate solution would you need to add? The pKa for acetate buffer is 4.75.

Answers

Answer:

Explanation:

Molarity of NaOAc needed

Using the Henderson-Hasselbalch Equation calculate base molarity needed given [HOAc] = 1.00M and pKa(NaOAc) = 4.75 and [HOAc] = 1.00m.

pH = pKa + log [NaOAc]/[HOAc]

5.00 = 4.75 + log[NaOAc]/[1.00M]

5.00 - 4.75 = log [NaOAc] - log[1.00M]

log [NaOAc] = 0.25 => [NaOAc] = 10⁰·²⁵ M = 1.78

Given 10ml of HOAc, how much (ml) 1.78M NaOAc to obtain a buffer pH of 5.00.

Determine Volume of Base Needed

(M·V)acid = (M·V)base => V(base) = (M·V)acid / (M)base

Vol (NaOAc) needed = (1.00M)(0.010L)/(1.78M) = 0.0056 liter = 5.6 ml.

Checking Results:

5.00 = 4.75 + log [1.78M]/[1.00M] = 4.75 + 0.25 = 5.00    QED.

The volume of 1.00 M sodium acetate solution needed to prepare an acetic/acetate buffer of pH 5.00 using 10.0 mL of 1.00M acetic acid solution is 17.8 mL.

We can find the volume of the acetate solution with the Henderson-Hasselbalch equation:

[tex]pH = pka + log(\frac{[CH_{3}COONa]}{[CH_{3}COOH]})[/tex]   (1)  

Where:

[CH₃COOH] = 1.00 M                      

[CH₃COONa] =?

pH = 5.00

pKa = 4.75

From equation (1), we have:

[tex] log(\frac{[CH_{3}COONa]}{[CH_{3}COOH]}) = pH - pKa [/tex]

[tex] \frac{[CH_{3}COONa]}{[CH_{3}COOH]} = 10^{pH - pKa} [/tex]

[tex] \frac{[CH_{3}COONa]}{[CH_{3}COOH]} = 10^{5.00 - 4.75} = 1.78 [/tex]

Now, the volume of the acetate solution is:

[tex]\frac{n_{CH_{3}COONa}/Vt}{n_{CH_{3}COOH}/Vt} = 1.78[/tex]  

Since the total volume is the same, we have:

[tex]\frac{n_{CH_{3}COONa}}{n_{CH_{3}COOH}} = 1.78[/tex]  

[tex] \frac{[CH_{3}COONa]_{i}*V_{b}}{[CH_{3}COOH]_{i}*Va} = 1.78 [/tex]  

Solving for Vb

[tex] Vb = \frac{1.78*[CH_{3}COOH]_{i}*Va}{[CH_{3}COONa]_{i}} = \frac{1.78*1.00M*10.0mL}{1.00 M} = 17.8 mL [/tex]

Therefore, we need to add 17.8 mL of sodium acetate solution.

Find more here:

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I hope it helps you!  

Cu + 2AgNO3 → Cu(NO3)2 + 2Ag

If a 40. g sample of Copper is used with an excess of silver nitrate, calculate the theoretical yield of silver. What is the percent yield of the silver, if 120 g was collected?

Answers

Answer:

[tex]m_{Ag}=135.8gAg[/tex]

[tex]Y=88.4\%[/tex]

Explanation:

Hello there!

In this case, according to the described chemical reaction, it is possible to compute the theoretical mass of silver as mass via the 1:2 mole ratio of copper to silver and their atomic mass in the periodic table, in order to perform the following stoichiometric setup:

[tex]m_{Ag}=40.gCu*\frac{1molCu}{63.55gCu}*\frac{2molAg}{1molCu}*\frac{107.87gAg}{1molAg}\\\\ m_{Ag}=135.8gAg[/tex]

Next, given the actual yield of 120 g, we compute the percent yield via:

[tex]Y=\frac{120g}{135.8g}*100\%\\\\Y=88.4\%[/tex]

Regards!

A granulated cylinder was filled to 30.0 mL with liquid. An unknown metal cylinder having a mass of 60.27 g was submerged in the liquid. The final volume of the liquid level was 45.2 mL.

Answers

Answer:

Explanation:

A graduated cylinder was filled to 30.0 mL with a liquid. An unknown metal cylinder having a mass of 60.27 g was submerged in the in the liquid. The final volume of the liquid level was 45.2 mL.

a. Calculate the density of the unknown metal cylinder.

b. The density of the liquid is 0.899 g/mL. What is the mass of the liquid in the graduated cylinder?

The particle on a ring is a useful model for the motion of electrons around the porphine ring, the conjugated macrocycle that forms the structural basis of the heme group and the chlorophylls. We may treat the group as a circular ring of radius 440 pm, with 22 electrons in the conjugation system moving along the perimeter of the ring. In the ground state of the molecules each state is occupied by two electrons.
A) Calculate the energy and angular momentum of an electron in the highest occupied level.
B) Calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels.

Answers

Answer:

Explanation:

The formula for determining the energy of state [tex]m_l[/tex] can be computed by using the formula:

[tex]Em_i = \dfrac{m_1^2h^2}{2I}[/tex]

Also, the momentum is:

[tex]l_2 = m_i h[/tex]

There are 22 electrons with two electrons in each of the lowest II energy levels so that the highest occupied states are [tex]m_1 = \pm 5[/tex]

The moment of inertia of an electron on a ring of radius 440 ppm is:

[tex]I = mR^2 \\ \\ = 9.109 \times 10^{31} \ kg (440 \times 10^{-12}) ^2 \\ \\ = 1.76 \times 10^{-49} \ kgm^2[/tex]

[tex]E_{\pm 5 } = \dfrac{25h^2}{2I} \\ \\ = \mathbf{7.89 \times 10^{-19} \ J}[/tex]

The angular  momentum is:

[tex]l_2 = \pm 5h \\ \\ = \pm 5 \tiems ( 1.05457 \times 10^{-34} \ Js)[/tex]

[tex]= \mathbf{5.275 \times 10^{-34} \ Js}[/tex]

B) Let's recall that:

The lowest occupied energy level is [tex]m_1 = \pm 6[/tex] which implies that the energy  [tex]E_{\pm 6}= 1.14 \times 10^{-18} \ J[/tex]

Thus;

[tex]\Delta E = E_{\pm 6} - E_{\pm 5} \\ \\ = 1.14 \times 10^{-18 \ J} - 0.79 \times 10^{-18} \ J \\ \\ = 0.35 \times 10^{-18} \ J \\ \\ 0.35 \times 10^{-18} \ J = hv \\ \\ 0.35 \times 10^{-18} \ J = h \dfrac{c}{\lambda}[/tex]

Hence, the radiation which would induce a transition that relates to the wavelength of about 570nm, a wavelength of visible light.

The smallest arteries in your body are called _____. arterioles capillaries veins bronchioles

Answers

Answer: arterioles

Explanation:

How many moles are in 2.5L of 1.75 M Na2CO3

Answers

Answer:

4.4 mol.

Explanation:

Hello!

In this case, since the formula for calculating the molarity is:

[tex]M=n/V[/tex]

Whereas n stands for moles and V for the volume in liters; we can solve for n as shown below when we are given the volume and the molarity:

[tex]n=V*M[/tex]

Thus, we plug in the given data to obtain:

[tex]n=2.5L*1.75mol/L=4.4mol[/tex]

Best regards!

Answer:

4.4 mol.

Explanation:

Have a great day

What is the molar mass of V(CO3)2?

Answers

Pretty sure 60.009 g/mol
60.009 g/mol :)

Just like the other person said ^, hope its right

Convert 5.7 kcal to its value in calories.

Answers

Answer:

5700

Explanation:

I guess this is free:)))): ((((

Answers

Answer:

tysm!!!! :D <<<33333

Explanation:

How many molecules are in 450.0 grams of aluminum fluoride(AIF3)?

Answers

Answer:

It would be exactly 5.3586262014272155. But if you were to round it up it would be 5.35.

Here is the answer:)

If you began a reaction with the following ions in solution, what would be the net ionic equation?
Na+, PO43–, Fe2+, and NO3–

Answers

Answer:

2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂

Explanation:

Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).

Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)

The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.

2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂

Cool air can hold less water vapor than warm air. Apply this fact to explain why clouds and precipitation form on the windward side of the mountain.​

Answers

The pressure is directly proportional to temperature (when the pressure decrease the temperature decrease too). Because the air parcel expands so the molecules will not interact with each other as much.

The energy of the particles does not change but the fact that the particles are more spaced out means the parcel is cooler.

so now, the warmer a parcel of air the more water vapor it can hold. so, if a parcel of air cools it's ability to hold water vapor drops and if it drops to a low enough point that is when the water vapor will condense and turn back into liquid water. This is how clouds and precipitation form on the the windward side of the mountain.

Clouds and precipitation form on the windward side of the mountain due to change in temperature and pressure.

What is the relation between pressure and temperature?

Temperature of any substance is directly proportional to the pressure of that substance.

If the temperature of the wind increases so that winds get warmer and at the same time pressure of gas also increases, due to which particles will go far from each other. After this warm air rises up and cools down will condenses to form clouds, after this precipitate will falls on the windward side of the mountain.

Hence due to temperature and pressure precipitate will form on the windward side of the mountain.​

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Given the reaction
3 H3PO4 + 2 Ba(OH)2 ⇒ BaPO4 + 6 H20
How many grams of precipitate could you make if you reacted 286.0 mL of 3.000 M H3PO4 with 855.0 mL of 1.400 M Ba(OH)2

Answers

Answer:

240.17 g Ba3(PO4)2

Explanation:

1. Determine the limiting reactant.

2H3PO4 + 3Ba(OH)2 --> Ba3(PO4)2 + 6H2O

moles H3PO4 = M x V = 3 x 0.286 = .858 moles H3PO4

moles Ba(OH)2 = M x V = 1.4 x 0.855 = 1.197 moles Ba(OH)2

ratio Ba(OH)2 : H3PO4 = 1.197: .858 = 1.39: 1

stoichiometric ratio Ba(OH)2 : H3PO4  = 3:2

Ba(OH)2is the limiting reactant

MM Ba3(PO4)2 = 601.92 g/mol

g Ba3(PO4)2 = moles Ba(OH)2 x(1 mol Ba3(PO4)2/3 moles Ba(OH)2) x (MM Ba3(PO4)2/ 1mol Ba3(PO4)2) = 1.197 x 1/3 x 601.92 = 240.17 g Ba3(PO4)2

Laura can use a toy car to demonstrate the force of gravity by doing which of these?
Letting the toy car roll down a ramp
Placing the toy car on the floor
Lifting the toy car onto a shelf
Pushing the toy car across a table

Answers

Answer:

letting the car fall down the ramp i got that right.

Explanation:

How do the causes of surface and deep water currents differ?
A. Surface currents are caused by wind deep water currents are caused by difference in water density
B. Surface currents are caused by the Coriolis effect deep water currents are caused by differences in water density
C. Surface currents are caused by differences in water salinity deep water currents are caused by differences in water temperature
D. Surface currents are caused by differences in water density deep water currents are caused by wind

Answers

Answer:

The answer is A. Surface currents are caused by wind deep water currents are caused by difference in water density.

Hydrofluoric acid and Water react to form fluoride anion and hydronium cation, like this HF(aq) + H_2O(l) rightarrow F(aq) + H_3O^+ (aq) At a certain temperature, a chemist finds that a 5.6 L reaction vessel containing an aqueous solution of hydrofluoric acid, water, fluoride anion, and hydronium cation at equilibrium has the following composition: Calculate the value of the equilibrium constant K_C for this reaction. Round your answer to 2 significant digits. K_C =

Answers

Answer:

Kc = 1.09x10⁻⁴

Explanation:

HF = 1.62g

H₂O = 516g

F⁻ = 0.163g

H₃O⁺ = 0.110g

To solve this question we need to find the moles of each reactant in order to solve the molar concentration of each reactan and replacing in the Kc expression. For the reaction, the Kc is:

Kc = [H₃O⁺] [F⁻] / [HF]

Because Kc is defined as the ratio between concentrations of products over reactants powered to its reaction coefficient. Pure liquids as water are not taken into account in Kc expression:

[H₃O⁺] = 0.110g * (1mol /19.01g) = 0.00579moles / 5.6L = 1.03x10⁻³M

[F⁻] = 0.163g * (1mol /19.0g) = 0.00858moles / 5.6L = 1.53x10⁻³M

[HF] = 1.62g * (1mol /20g) = 0.081moles / 5.6L = 0.0145M

Kc = [1.03x10⁻³M] [1.53x10⁻³M] / [0.0145M]

Kc = 1.09x10⁻⁴

what energy is walking?
A. light energy
B. sound energy
C. Thermal energy
D. Mechanical energy
E. electrical energy

Answers

Answer:

Mechanical

Explanation:


Mechanical Energy - is moving energy. It is the form that we most see around us. All moving objects produce mechanical energy. The movements within machines is also mechanical energy.
Examples: People, a rolling bicycle, moving gears, and running cars.

I have a balloon that can hold 100. liters
of air. If I blow up this balloon with 3.0
moles of oxygen gas at a pressure of 1.0
atmosphere, what is the temperature of
the balloon?

Answers

Answer:

T = 4.062V

Explanation:

from PV = nRT => T = PV/RT

P = 1 atm

V = Final Volume

n = 3 moles

R = 0.08206 L·atm/mol·K

T = ?

T = 1 atm · V(Liters)/(3 moles)(0.08206L·atm/mol·K) = 4.062·V(final) Kelvin

The temperature of the balloon is 406 K

We'll begin by listing out what was given from the question. This is shown below:

Volume (V) = 100 L

Mole of oxygen (n) = 3 moles

Pressure (P) = 1 atm

Temperature (T) =?

We can obtain the temperature of the balloon by using the ideal gas equation as shown below:

PV = nRTNOTE:

P is the pressure.

V is the volume.

n is the number of mole

R is the gas constant (0.0821 atm.L/Kmol)

T is the temperature.

Applying the ideal gas equation, we have:

PV = nRT

1 × 100 = 3 × 0.0821 × T

100 = 0.2463 × T

Divide both side by 0.2463

T = 100 / 0.2463

T = 406 K

Therefore, the temperature of the balloon is 406 K

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Fill in the blanks. 3NH3

Answers

Answer:

3, 9, 3

Explanation:

The coefficient of 3 tells us that there are three molecules (the chemical unit of NH3). Each molecule of ammonia (NH3) is made up of 1 atom of nitrogen bonded to 3 atoms of hydrogen.

Since there are three molecules, we have three times the amount of atoms there are in one molecule.

3 x 1 = 3 nitrogen

3 x 3 = 9 hydrogen

The percent composition by mass of nitrogen in NH OH (gram-formula mass = 35 grams/mole) is equal to

Answers

Answer:

the percentage composition of mass of nitrogen in NH OH is 42.86 %

What is the mass of 0.063x10^-4 moles of aluminum sulphate ?

Answers

Answer:

The mass of 0.063*10⁻⁴ moles of aluminum sulphate  is 2.15*10⁻³ grams.

Explanation:

Aluminum sulfate Al₂(SO₄)₃ has a molar mass of 342.15 g/mol.

Molar mass is the amount of mass that a substance contains in one mole of a substance, which can be an element or a compound.

So in this case you can apply the following rule of three: if 342.15 grams are present in 1 mole of aluminum sulfate, how much mass is present in 0.063*10⁻⁴ moles of the compound?

[tex]mass of aluminum sulphate=\frac{0.063*10^{-4}moles*342.15 grams }{1 mole}[/tex]

mass of aluminum sulphate= 2.15*10⁻³ grams

The mass of 0.063*10⁻⁴ moles of aluminum sulphate  is 2.15*10⁻³ grams.

Which type of rock does Florian predict these pieces will change into when subjected to heat and pressure?

Answers

Answer:

The Florian predict the metamorphic rocks because it changes when subjected to heat and pressure.

Explanation:

i hope this helps

In a single replacement reaction, the chloride ion in NaCl can be replaced
by

a. potassium
b. carbon
c.fluorine
d.neon

Answers

Answer:

c. fluorine

Explanation:

A single replacement reaction is defined as the chemical reaction in which a strong molecule replaces the weak molecule from a compound.

In a single replacement reaction, the chloride ion in NaCl can be replaced     by fluorine and gives Sodium fluoride as fluorine (F) is stronger than chlorine (Cl) and from other given molecules also. So the single replacement reaction between NaCl and F will be:

NaCl + F2 => NaF + Cl2

Hence, the correct answer is "c. fluorine".

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Help please!!!!!!!!!!!!! What observation supports the claim that earth rotates Help Ill mark you brain list please U.S. cities grew quickly during the early 1800s because:A. declining immigration created more space in cities.B. industrialization created new jobs in cities.O C. Catholics and Protestants agreed to share cities.D. poor transportation made it hard to leave cities. helllllllppppp plzzzz If f(x) = 2x + 1 then f(3)= The giraffes roam 612 acres of grasslands and the tigers roam 346 few acres. How many acres do they roam combined? [tex]y-5\geq -7[/tex] How do I make a turnakit to stop bleeding? Lousina has 4 yards of fabric. she uses 2/5 yard of fabric to make a doll dress. How many doll dresses could Lousina make with the fabric? DUE BY 10:00 AM (30 minutes from now) (Will give BRAINLIST)In a well-constructed paragraph, explain how the creature compares and contrasts his situation to Adams. (In the biblical creation story, God creates and cares for Adam.) Use evidence from Volume II, Chapter 2 of Gris Grimly's Frankenstein in your answer.200-300 Words If a reaction is endothermic,1 pointMore energy is released when the bonds in the products are formed than is used tobreak the bonds in the reactantsThe temperature increasesThe same amount of energy is used to break the bonds of the reactants as is releasedwhen the bonds in the products are formed OIt takes more energy to break the bonds of the reactants than is released when thebonds in the products are formed Bonus Question : "There are two kinds of evil people in this world: those that commit evil and those that witness and do nothing" Which is worse in your opinion and what can be done to eliminate the violence against one another? Which of the following is true about evaporation from land surface as compared to precipitation over them?(1 Evaporation is equal to the precipitation2 Evaporation is more than the precipitation3 Precipitation is more than the evaporation4 Precipitation and evaporation have no relationship choices: tener ganas, tener hambre, tener que, tener razn, tener sed, tener sueoFRANCISCO Son las once de la noche! Vamos a dormir. Buenas noches. JAVIER No, no (1) ____tener sueno_________________________. Voy a comer algo (something) porque (2) _____________________________.FRANCISCO Est bien. Yo voy a dormir.JAVIER No! Nosotros (3) _____________________________ estudiar para el examen. FRANCISCO (4) _____________________________. Maana es el examen de qumica. JAVIER S, vamos a estudiar. Yo no (5) _____________________________ de estudiar, pero es importante 3. If a+b=c, then what is the average value of a,b are c? Identify ethnocentrism's polar opposite concept. Please answer Read this excerpt from the article "Clemente's Impact Wanes in Puerto Rico 40 Years after His Death."In the days that followed, as Clemente's death was accepted as reality, a photo of his 7-year-old son Roberto Jr. kissing a poster with his father's picture became as heart-wrenching and iconic in Puerto Rico as the image of JFK Jr. saluting his father's coffin was in the U.S.Which is the best source to use to enhance the information in this excerpt?A) a magazine article about JFK Jr.B) a copy of the image of Clementes sonC) a website describing Puerto Rican photographersD) an almanac entry about Clementes baseball career If five times a whole number increased by 3 is less than 13, then find the solution set.