What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?

Answers

Answer 1

Answer:

39

Explanation:

Total protons + total neutrons = mass number


Related Questions

What is the molarity of a solution that contains 2 moles of KCl in 4 L of solution? a 2.0 M b 0.5 M c 0.25 M d 8.0 M

Answers

Answer:

A.) 2.0 M

Explanation:

Molarity=mole of solutes/Liters of solution so M=mol/L

2moles/4 L =2 M

what happens to particles during a physical change?

Answers

Answer:

im pretty sure they heat up

Explanation:

as they use energy to go from solid to liquid to gas, they need heat to do so as they have a melting and boiling point

What is meant by “normal” when you are asked for normal boiling and melting points?

Answers

Answer:

Normal boiling point is the temperature at which a liquid boils at 1 atmosphere of pressure.

Explanation:

quick question plz . .....Which one of the following is acidic oxide?

A. K2O

B. CO2

C. MgO

D. Al2O3

Answers

Answer:

B

Explanation:

its an acidic oxide, it disolves in water to form carbonic acid which is an acid

What is h2OO??????????

Answers

The answer is : H2O is water

Please Help In need of chemistry help

The reaction CH4 + Br2 → CH3Br + HBr is an example of

1.Addition
2.Polymerization
3.Substitution
4.Hydrogenation

Answers

it’s an example of substitution

what is chemistry? ​

Answers

Answer:the branch of science which examines the material of the universe and changes that these materials undergo

Chemistry deals with composition,structure,properties of matter and changes that these materials undergo

how much volume do the gas molecules take up in an inflated balloon

Answers

Answer:

The volume of a gas is determined by the volume of the container it is in. Gases take the shape of their container and the volume of the container....

Explanation:

What happens to the volume or size of a balloon as it rises in the air?

When a balloon goes up higher in the air, its size will increase. Since there's less air in the upper atmosphere, there's less stuff pushing back on the balloon, and hence the pressure is lower, which allows the balloon to expand.

Is pressure inside a balloon greater?

The pressure inside the balloon is higher than the pressure on the outside. ... And the direction of airflow is always from higher to lower pressure. If the pressure was same then there would be no airflow and if the pressure outside was higher , air will flow from outside to the inside of the balloon.

What is the relationship between volume and pressure?

Boyle's law is a gas law, stating that the pressure and volume of a gas have an inverse relationship. If volume increases, then pressure decreases and vice versa, when temperature is held constant. Therefore, when the volume is halved, the pressure is doubled; and if the volume is doubled, the pressure is halved.

Mark as brainliest if liked it. Thanks hope this helps

It depends on how many volume the container is in

What is the normal boiling point of of a solution containing 64.5g of non volatile quinoline ( MW 129 ) in 500 g of benzene when the normal boiling point is 80.10 and KB = 2.50

Answers

Answer:

THE NORMAL BOILING POINT OF A SOLUTION CONTAINING 64.5 g OF QUINOLINE IN 500 g OF BENZENE IS 82.6 C

Explanation:

Boiling point = old boiling point + molarity * boiling point constant (Kb)

First, you calculate the number of moles of quinoline in the solution

number of moles = mass / molar mass

Since the molar mass of quinoline has been given as 129 g/mol

number of moles = 64.5 g / 129 g/mol

number of moles = 0.5 moles.

Next is to determine the molarity:

molarity = number of moles of solute / kilogram of solvent

molarity = 0.5 moles / 500/1000 kg

molarity = 0.5 / 0.5

molarity = 1 M

The new boiling point can then be calculated using the formula:

B. P = old B.P + Kb * molarity

B.P = 80.10 + 2.50 * 1

B.P = 80.10 + 2.50

B.P = 82.6 degree celsius

Which body system processes food into a useable source of energy?

Answers

Answer:

Glucose, found in the food animals eat, is broken down during the process of cellular respiration into an energy source called ATP. When excess ATP and glucose are present, the liver converts them into a molecule called glycogen, which is stored for later use.

The digestive system processes food into a usable source of energy.

In which state of matter does heat travel fastest and slowest?

Answers

Answer:

Heat travels faster in solids.

Heat travels slower in gases.

Explanation:

The state of matter in which heat travels in fastest way is solid and in gaseous state heat travels in slowest way.

What is heat transfer?

Heat transfer is a process in which heat can travel from one body to another body or from high temperature to low temperature.

In solid state heat will travel in the fastest way because molecules are arranged very close to each other and heat will travel through conduction process. And in gaseous state heat will travel with slowest way as molecules are arranged in very distance.

Hence in solid, heat travels in fastest way and in gases heat travels in slowest way.

To know more about heat conduction, visit the below link:

https://brainly.com/question/1121702

to the
of the substances.
DONE

Answers

Answer

what do you mean?

Explanation:

im confused

Answer:

Sorry. I don't understand

Explanation:

Which set of phrases best lists the characteristics of asexual reproduction?

one parent, offspring are not identical to the parent

one parent, offspring are identical to the parent

two parents, offspring are not identical to the parents

two parents, offspring are identical to the parents
I need this answer fast ASAP.

Answers

Answer:

one parent, offspring are identical to the parent

Explanation:

Answer:

one parent, offspring are identical to the parent

Explanation:

asexual reproduction is a form of reproduction that does not require two gametes to fuse. Asexual reproduction results in offspring that are known as stable clones, meaning that their genetic makeup is stable and doesn't change between generations

Triangle W Z Y is cut by bisector Z X. The lengths of sides Z W and Z Y are congruent. ZX bisects ∠WZY. If the measure of ∠YXZ is (6m – 12)°, what is the value of m?

Answers

Answer:

m = 17

Explanation:

From the question we were given that

Triangle WZY is bisected by ZX; ZW = ZY

∠YXZ = (6m – 12)°

Based on the characteristics of the triangle, we see that triangle WYZ is an isosceles triangle (that is, triangle WXZ is equal to triangle YXZ)

<YXZ = <WXZ = 90°

Using ∠YXZ  = (6m – 12)°

We have:

(6m – 12)° =  90°

6m = 90 + 12 ⇒ 6m = 102

m = 102 ÷ 6 = 17

m = 17

We therefore see that m is equal to 17

Answer:

B: 17

Explanation:

how many electrons does phosphorus need to gain to have a stable outer electron shell
1
2
3
4​

Answers

Answer:

3

Explanation:

Phosphorous valence is 5. so to get stable electronic configuration it has to gain 3 more electrons to its outer shell

Answer:

3

Explanation:

luckily, every phosphorus atom is looking to gain 3 electrons. It's a perfect match. But something to notice though, look how they have a bond with six electrons. That is called triple bond.

Which material is most likely to be a base?
salt water
vinegar
coffee
orange juice

Answers

Answer:

Cooffee

Explanation:

the answer is coffee because coffee might be bitter

Answer:Coffee

Explanation:Water is neutral, while the other answers are mostly organic acids but salt water is neither acidic nor basic

You make an iron (II) sulfate solution with a molarity of 2.1 M. If the solution is 500 mL total, how many grams of iron (II) sulfate is that?

Answers

Answer:

Explanation:

2.1>1000

?>500

(500×2.1)÷1000=1.05moles

Mass= molesx molar mass

1.05×(56+32+(16×4))

1.05×152=159.6g

Identify this molecule

Answers

Answer:

Ribose

Explanation:

This is the pentose sugar found in RNA commonly.

What are the 5R principles of which we can make a difference in our environment?

Answers

Answer:

The 5R's are Reuse, Reduce, Recycle, Repair and Recover.

How many liters of hydrogen gas is produced from 3.712 g of magnesium with 104.2ml of 1.385 mol/L HCL (aq) at SATP? Please show your work and explain it. I really need help with this question, it's on one of my quizzes.

Answers

Answer:

[tex]V=1.61L[/tex]

Explanation:

Hello,

In this case, the undergoing chemical reaction is:

[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]

Next, we compute the reacting moles of each reactants:

[tex]n_{Mg}=3.712gMg*\frac{1molMg}{24.305 gMg}=0.153molMg[/tex]

[tex]n_{HCl}=1.385\frac{molHCl}{L}*0.1042L=0.144molHCl[/tex]

Then, as magnesium and hydrohloric acid are in a 1:2 molar ratio 0.153 moles of magnesium will completely react with 0.306 moles of hydrochloric acid yet we only have 0.144 moles, therefore, limiting reactant is hydrochloric acid. Thus, we compute the produced moles of hydrogen:

[tex]n_{H_2}=0.144molHCl*\frac{1molH_2}{2molHCl} =0.072molH_2[/tex]

Finally, we use the ideal gas equation with T=298K and 1atm (STP conditions) to compute the liters of hydrogen gas:

[tex]PV=nRT\\\\V=\frac{nRT}{P}=\frac{0.072mol*0.082\frac{atm*L}{mol*K}*273K}{1atm}\\ \\V=1.61L[/tex]

Best regards.

Diagrams, tables, and graphs are used by scientists to

Answers

Answer:

Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information • Graphs are created from data tables • hope that helps love!

what is the symbol for Lithium, Iron, and Helium

Answers

Lithium=li

Iron=Fe

Helium=He

I don't say u must have to mark my ans as brainliest but if u think it has really helped u plz don't forget to thank me....

Answer:

lithium symbol=li helium= he and iron =i

How are ironic bonds and covalent bonds different and how are they different?

Answers

Ionic bonds are forces that hold together electrostatic forces of attractions between oppositely charged ions. Ionic bonds have an electronegativity difference greater than or equal to 2. Covalent bonds have an electronegativity difference that is less than 2.

what is freshly prepared FeSO4 used in the brown ring test​

Answers

Answer:

Freshly prepared ferrous sulphate is used in brown ring test, because if FeSO4 is stored or it is the old one then it reacts with atmospheric oxygen and gets oxidized to form a corrosive brown-yellow coating of basic ferric sulphate, which is an adduct of ferric oxide and ferric sulphate

HEYA FRIEND

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HERE'S YOUR ANSWER

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It is used in brown ring test because , if Fe2So4 is stored or it is old one then it reacts with atmospheric oxygen and gets oxidized to form a corrosive brown yellow coating of basic ferric sulphate , which is an adduct of ferric oxide and ferric sulphate.

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HOPE IT WILL HELP YOU UP

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KATË

What is the pH of a 6.4x10^-10 m OH- solutions

Answers

Answer:

pH: 4.80617997398

pOH: 9.19382002602

[H+]: 1.5625E-05

[OH-]: 6.4E-10

ACID

Hope it helps :)

Name the process that releases carbon dioxide into the atmosphere.

Answers

cellular respiration

What are the two ways that humans lose heat? PLS help thank you!

Answers

Answer:

Evaporation, Radiation

Explanation:

Evaporation of water from your skin if it is wet (sweating). ...

Radiation (similar to heat leaving a woodstove).

to well
Which of the
of the following is a way to use
water economically
a construction of bewris
b Rainwater harvesting
c Drup irrigation
d Infitration

Answers

Answer:

c Drup irrigation

Explanation:

Hope it helps you.

Plz mark as brainliest plz.

Draw an alkyl bromide with proper stereochemistry that can be used to synthesize the given alkene as the exclusive product via an e2 reaction.

Answers

Answer:

See explanation below

Explanation:

You forgot to put the picture to do so. In this case, I manage to find one, and I hope is the one you are looking for. If not, then post it again and I'll gladly help you out again.

According to the picture with the answer, we have a cyclohexane with 4 methyl groups there. Two of them are facing towards the molecule with a darker bond. This means that the alkyl bromide, should have a bromine in one of the bonds, and in order to produce an E2 reaction, this bromine should be facing in the opposite direction of the methyl groups which are facing towards. This is because an E2 reaction occurs with the less steric hindrance in the molecule. If the bromine is in the same direction as the methyl group, it will cause a lot more of work to do a reaction, and therefore, an E2 reaction. I will promote instead a E1 or a sustitution product.

Therefore the alkyl bromide should be like the one in the picture 2.

Which factor affects gravitational potential energy but not elastic potential energy?

Answers

Answer:

spring constant. acceleration due to gravity. distance from a given position. amount of matter in the object.

Explanation:

hope this helps you :)

Answer:

spring constant

Explanation:

Other Questions
Question 7Read the following passage and answer the question.The World War II saw the beginning of the atomic age as it experienced a differentmindset. The Americans wanted to end the war that prolonged for years. Therefore,the United States developed bombs with advanced technology. As a result, theAmericans came up with a plan to develop atomic bombs.What would be an appropriate topic for the given passage?A: Technological developments in the 20th centuryB:The World War and the United StatesC:The beginning of the atomic ageD:The dawn of the atomic ageexplain answer All rectangles are parallelograms. True or False. The top of the circular table has a radius of 16 inches.What is the circumfrence of the tabletop? Use 3.14 for pie "Addison Corp. is considering the purchase of a new piece of equipment. The equipment will have an initial cost of $522,000, a 3 year life, and no salvage value. If the accounting rate of return for the project is 6%, what is the annual increase in net cash flow Choose the correct coefficients to balance the following equation: __CaCO3 + __HC; Produces __CaCl2 + __CO2 + __H2O The following data are accumulated by Watershed Inc. in evaluating two competing capital investment proposals: Project A Project Z Amount of investment $55,000 $50,000 Useful life 12 years 15 years Estimated residual value $5,000 $6,000 Estimated total income over the useful life $57,600 $63,000 Determine the expected average rate of return for each project. Which statement about x-5- x = 5 is true? Consider the following 2011 data for Newark General Hospital (in millions of dollars):__________. Static Flexible Actual Budget Budget Results Revenues $4.7 $4.8 $4.5Costs 4.1 4.1 4.2Profits 0.6 0.7 0.3Calculate and interpret the profit variance.=Actual profit-Static profit=$0.3-$0.6=-$0.3There is an unfavorable profit variance which means that the company earned less that it prepared for.Calculate and interpret the revenue variance.=Actual revenues-Static Revenues=$4.5-$4.7=-$0.2There is an unfavorable revenue variance, because the company sold less than it planned for.Calculate and interpret the cost variance.=Static Cost-Actual Cost=4.1-4.2=-$0.1There is an unfavorable cost variance, this means that the company spent more than it planned for.Calculate and interpret the volume and price variances on the revenue side.Volume variance=Flexible Revenue-Static Revenue=$4.8-$4.7=$0.1Favorable because the company sold more units than it planned for.Price variance=Actual Revenues-Flexible Revenues=$4.5-$4.8=-$0.3The answer is unfavorable because the company sold it products at a lower price than plan which might have actually resulted to the increase in actual volume sold.Calculate and interpret the volume and management variances on the cost side.Volume variance=Static cost Actual Cost=$4.1-$4.1=$0Favorable which means that regardless of the fact that the company sold more units, the company produce the same number of units it plan for.Management variance=Flexible Cost Actual Costs =$4.1-$4.2=$0.1This is unfavorable which means maybe as a result of the higher units sold, the company had to spend more in servicing these units resulting to cost inefficiency for the period.How are the variances calculated above related?The above variances are associated, as the increase in volume, should increase the revenue and cost proportionality. However, it has not increased in the same portion. Therefore, there are unfavorable variances. Triangle ABC has measures a = 2, b = 2, and mzA = 30.What is the measure of angle B?15304560 With the charactermany scholars believe that Chaucer is indirectly criticizing the church which inequality is represented by this graph Following Dietary GuidelinesAccording to the Dietary Guidelines for Americans, which foods should you increase and decrease within your diet?Sort each food into the appropriate categoryFoods to IncreaseFoods to Decreasebaconsalty snackssalmonwheat breadvegetablessugary drinksPls help. Ill give you brainiest Which algebraic expression represents the oference of 54 and a number?2 glass co. had net income of $70,000 during the year. Depreciation was $10,000. the following information is available: accounts receivable increase (sale price $100,000) non trade notes payable increased by 50,000, equipment purchases increased by 40,000 account payable increase 30,000. what amount should galss report as net cash provided by investing activities Would the midpoint (2,2) be correct? What is Chichicastenango? Rio reads a notice about the car park at the hospital. The notice below has a word missing.Choose the correct word so that the sentence makes sense.Sorry, you cannot use our hospital car parkSelect...it is closed for repair. What is the probability of rolling 2 sixes in a row with a single die? Suppose you win the lottery and have two options: A. Take $1 million now. B. Take $1.2 million to be paid out as 300,000 now and then $300,000 a year for 3 years. Which is the better deal? Assume that the interest rate is 10%. Please show your work. (4 point) which set of cell organelles are involved in cell division 1.Lysosome and nucleus 2.Golgi bodies and nucleus 3.Centrosome and nucleus 4.Mitochondria and nucleus