What is a rule for determining the mass number of an atom or ion?

Answers

Answer 1

Answer:

The mass number of the atom is equal to the sum of the number of protons and neutrons in the nucleus

Explanation:

Each proton and each neutron weigh one amu( atomic mass unit), adding together the neutrons and protons and multiplying by 1 amu you get the mass of an atom


Related Questions

Would you expect manganese(II) oxide, MnO, to react more readily with HF(aq) or NaOH(aq)?

Answers

Answer:

NaOH(aq)

Explanation:

NaOH(aq) is known to precipitate Mn^2+ ions according to the following reaction; Mn^2+(aq)+2OH^−(aq)↽−−⇀Mn(OH)2(s)

Hence, manganese(II) oxide reacts more readily with NaOH(aq) under ordinary conditions precipitating the metal hydroxide solid. This is one of the characteristic reactions of Mn^2+.

How much eat is absorbed when 50.0g of water changes from 25.0 Celsius to 37.0 Celsius?

Answers

27 I think beacuse if you subtract
4.186 j/g. X 50g x (37-25) =
2,511 joules or 2.5 kilo joules
Or 2.38 btu


4.186 is specific heat of water per gram per deg C at sea level
Times mass of 50 grams
Times delta T of the water


2530 joules when cross checked by plugging into an online calculator

Using dimensional analysis, how many kilometers are there in 34 inches?

Answers

Answer:

There are many ways to figuring this out: you could use a ruler, a calculator or scrap paper.

Explanation:

This is not an actual flat out answer, but it’s helpful methods to getting the answer the next time you are stuck. Hope you are having a nice day. Bless your heart and soul.

This is a science question.

What is the acceleration of this helicopter?

Answers

Answer:

7m/s

Explanation:

Is the acceleration of the helicopter

plsssssssssssssssssssssssssssssssssssssssss help me

Answers

Answer:

C

Explanation:

A year is a complete revolution around the Earth

Which type of bond is salt? a. covalent b. valence c. metallic d. ionic

Answers

Answer:

D. Ionic

Explanation:

It has ionic bonding! Good luck ^^

The first noble gas with a Lewis Structure with 8 dots is

A. Ar
B. Kr
C. He
D. ne

Answers

Answer:

C) He

Explanation:

Helium is one of the noble gases and contains a full valence shell. Unlike the other noble gases in Group 8, Helium only contains two valence electrons.

A divalent metal oxide contains 60 % of metal. What is atomic weight of metal ?​

Answers

Atomic weight of metal : 24

Further explanation

Proust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements

Divalent metal oxide=XO

MW O = 16

MW XO₂ =  X+16

[tex]\tt \%mass=\dfrac{Ar~X}{X+16}\times 100\%\\\\0.6=\dfrac{X}{X+16}\\\\0.6(X+16)=X\\\\0.6X+9.6=X\\\\0.4X=9.6\rightarrow X=24[/tex]

Explain why the Earth has four different seasons​

Answers

Answer:

Earths rotation

Explanation:

Answer:

because if there was not four diferent season we would not have a day or a night because we would not be moving

Explanation:

Suppose that green spheres represent chlorine atoms, yellow-green spheres represent fluorine atoms, white spheres represent hydrogen atoms, and all the molecules are gases

Answers

Answer:

a. Reactants: F₂ and HCl molecules

Products: Cl₂ and HF

b. 4HCl + 2F₂ ----> 4HF + 2Cl₂

c. Single replacement reaction

Note: The question is not complete. The complete question is found below as well as in the attachment.

Suppose that green spheres represent chlorine atoms, yellow-green spheres represent fluorine atoms, white spheres represent hydrogen atoms, and all the molecules are gases:

a. write a formula for each of the reactants

b. write a balanced equation for the reaction

c. indicate the type of reaction as combination,decomposition, single replacement, double replacement, or combustion

Explanation:

a. From the models shown in the diagram, The reactants are F₂, HCl while the products are Cl₂ and HF respectively

b. Equation for the reaction is given below;

4HCl + 2F₂ ----> 4HF + 2Cl₂

c. The reaction is single replacement reaction such that fluorine gas molecules replace the chlorine atoms in hydrogen chloride to form hydrogen fluoride with the liberation of chlorine atoms as gaseous molecules.

Among the groups of elements listed below, which have the same number of electrons in their outermost energy levels?
O NP. As, Sb
None of these
OK, Ca, Rb, Sr
OLI, B, C F
O Na Mg, ALS

Answers

Answer:

N, P, As, Sb

Explanation:

Elements present in the same group having same number of valence electrons. The first option is correct from given options because nitrogen, phosphorus, arsenic and antimony are present in same group thus having same number of electrons in outer most  energy level.

Electronic configuration of N:

N₇: [He] 2s² 2p³

Electronic configuration of P:

P₁₅: [Ne] 3s² 3p³

Electronic configuration As:

As₃₃: [Ar] 3d¹⁰ 4s² 4p³

Electronic configuration Sb:

Sb₅₁: [Kr] 4d¹⁰ 5s² 5p³

Here it is clear from electronic configuration all these elements have five number of valence electrons.

what is S oxidation number

Answers

the answer to you question is -2

A given mass of gas in a rigid container is heated from 100 °C to 300 °C. Which of the following best describes what will happen to the pressure of the gas? The pressure will

Answers

Answer:

Pressure will increase by a factor of 3.

Explanation:

PV = nRT —> Ideal gas equation.

Taking into account the Gay-Lussac's Law, the pressure will increase by a factor less than three.

Gay-Lussac's law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of collisions against the walls increases, that is, the pressure increases. That is, the pressure of the gas is directly proportional to its temperature.

In summary, when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases.

Mathematically, Gay-Lussac's law indicates that the ratio of pressure to temperature is constant:

[tex]\frac{P}{T} =k[/tex]

Studying two different states, an initial state 1 and a final state 2, it is satisfied:

[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]

In this case, a given mass of gas in a rigid container is heated from 100 ° C to 300 ° C, that is, it is heated from 373 ° K to 573 ° K. This indicates that the temperature is increasing by a factor less than three. Since pressure is directly proportional to temperature, pressure must increase in the same proportion.

Finally, the pressure will increase by a factor less than three.

Learn more:

https://brainly.com/question/4147359?referrer=searchResults

How do slab pull forces affect plate motion? Choose the correct answer.


Uplifted mantle causes plates to move apart.

Convection currents drive the plate downward to move it.

Earthquakes break the crust into smaller plates to make motion easier.

The weight of the subducted plate produces a force to continue moving the plate.

Answers

Answer:

The weight of the subducted plate produces a force to continue moving the plate.

Explanation:

Isopentyl acetate is the molecule largely responsible for the aroma and taste of bananas. It is made up of carbon, hydrogen, and oxygen. Combustion of a 3.256-g sample of isopentyl acetate produces 7.706 g CO2 and 3.156 g H2O. Using these results, what is the correct empirical formula for isopentyl acetate?

Answers

Answer:

Explanation:

7.706 g of CO₂ will contain 12 x 7.706 / 44 g of C

= 2.1 g of C .

This will be contained in 3.256 g of isopentyl acetate

3.156 g of H₂O will contain 2 x 3.156 / 18 g of H

= .351 g of H

This will be contained in 3.256 g of isopentyl acetate

Rest will be oxygen

amount of oxygen in 3.256 g of isopentyl acetate

= 3.256 - ( 2.1 + .351 )

= .805 g

ratio of C , H , O in isopentyl acetate

= 2.1 g : .351 g : .805 g

2.1 / 12 : .351 / 1 : 0.805 / 16 ratio of moles

= .175 : .351 : .05  ratio of moles

= 3.5 : 7.02: 1

= 7 : 14 : 2

empirical formula of  isopentyl acetate

= C₇ H₁₄ O₂ .

The rows in the periodic table are called periods.
What is true about elements in the same period?
A. They have the same atomic mass.
B. Their magnetism increases in strength from left to right.
C. Their atomic numbers increase by 1 from left to right.
D. They have similar chemical properties.

Answers

Answer: C) Their Atomic Numbers increase by 1 from left to right

Answer: C

Explanation:

Examine the layers of rock. How does layering provide evidence for determining geologic age?

Answers

Well I can’t see the rocks but, to determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones.



Hope this helped! <3

Answer:

the deeper you go down in to the rock the older the fossils get.

Explanation:

layering can provide evidence because the deeper you go down in to the rock the older the fossils get. So when the scientists go in to the rock they can say what animals lived in that time and what animal was the oldest.

Write the chemical formula for gold (I) sulfide.

Answers

Answer

Au2s

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argon is an inert gas give reason.​

Answers

Answer:

You're right

Argon is an inert gas.

Explanation:

Answer:

Argon is in zero group and it has octet structure so argon will not react with any compound

Consider the equation:

Ca+O2→CaO

What needs to be done in order to balance the equation?


Place a 2 in front of the Ca and the CaO.

Place a 2 in front of the O2 and the CaO.

Place a 2 in front of the CaO only.

Place a 2 only in front of the Ca.

Answers

the first one would be the best answer

Which of the following is a subsurface event that takes place during the rock cycle?

Group of answer choices

Cementing

Erosion

Melting

Weathering

Answers

Answer:

Melting

Explanation:

Could not have been erosion because erosion happens on the surface.

Could not have been weathering because weathering happens on the surface.

So we only have Cementing and Melting left....

The answer is melting, I got 100% on my test.

Hope this helps!!!! :D

Please give brainliest!!!

Answer:

D

Explanation:

In the rock cycle, surface events takes place at the surface of earth. Thus,

weathering and erosion are surface events, while the subsurface events he take place in the deeper section of the earth . Examples of sub surface events are plate tectonics and mountain building or anything that takes place in the inner core of earth.

Methanol, propan-1-ol and ethanol has boiling point of 65 degree celsius, 97 degree celsuis, 87 degree celsuis respectively. A student uses fractional distillation to separate a mixture of these compound. State which liquid will be collected in the second fraction and explain why

Answers

Answer:

ethanol

Explanation:

Methanol has a boiling point of 65°C, propan-1-ol has a boiling point of 97°C and ethanol has a boiling point of 87°C

Fractional distillation is used for separating miscible liquids through the use of the different vapor pressure properties of the liquids. As the mixture is heated up, components start to vaporize according to their boiling points. The component with the least boiling point vaporizes first while the component with the highest boiling point vaporizes last.

This means that methanol would vaporize at the first fraction because it has the lowest boiling point followed by ethanol at the second fraction and then propan-1-ol at the last fraction.

Glycerol has a density of 1.26g/mL. What is the mass of 3000.mL of glycerol?

Answers

Hey you got a picture you can call the number one phone call you got it and send

If 0.484J of heat is added to 0.1372g of water, how much will the temperature increase?

0.263 °C
0.927 °c
0.843 °C
0.460 °C

Answers

Answer:

ΔT = 0.843 °C

Explanation:

Given data:

Heat added = 0.484 J

Mass of water = 0.1372 g

Temperature increase = ΔT = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Specific heat capacity of water is 4.184 j/g.°C

Now we will put the values in formula.

0.484 j = 0.1372 g × 4.184 j/g.°C× ΔT

0.484 j = 0.574j/°C× ΔT

ΔT = 0.484 j / 0.574j/°C

ΔT = 0.843 °C

Etiquetas de productos de casa formula química, nombre de la formula, y el nombre del producto. Ejemplo NaCL, Cloruro de sodio, sal.

Answers

Answer:

Azucar, bicarbonato de sodio, lavandina, vinagre, amoniaco.

Explanation:

Podemos numerar estos compuestos

Azucar → Sacarosa → C₁₂H₂₂O₁₁

Lavandina → Hipoclorito de sodio → NaClO

Vinagre → Ácido acético → CH₃COOH

Bicarbonato de sodio → NaHCO₃

Amoníaco → NH₃

What effect does the spinning of the earth's core have?
A.it creates gravity
B. it creates matter
C. it creates mass
D. it creates the earths magnetic field.

Answers

Answer:

c

Explanation:

its c

Earth contains a spinning electric filed. The spinning of earth core creates its magnetic field. Thus, option D is correct.

What is a spinning body?

A body which rotates in its own axis is called a spinning body. Earth rotates about its along with revolving around sun.  The outer core of earth generates electric current. This is called telluric current.

Flow of this current creates an electric current which is parallels to the surface of earth. The direction of magnetic field lines will be perpendicular to the direction of current. But it comes stronger when parallel to current.

A rotating electric current results in the generation of a magnetic field. Thus spinning of  earth core generates a magnetic field and therefore, option D is correct.

To learn more about magnetic field, refer the link below:

https://brainly.com/question/11514007

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What part of the earth are the plate tectonics on?
lithosphere

outer core

asthenosphere

inner core

Answers

Outer core, thank me later
It should be outer core, if not lithosphere

The element magnesium is a
O Group 12, Transition Metal
O Period 3, Alkaline Earth Metal
Period 4. Alkali Metal
O Period 4, Halogen

Answers

Group 2
Period 3
Alkaline Earth Metal

A sealed plastic bottle of apple juice is placed in freezer. Which statement describes what is happening while the juice is changing form a liquid to a solid?

A.) Kinetic energy is increasing. B.) Particle motion is coming to a complete stop.
C.) Particle speed is staying the same.
D.) Temperature is decreasing steadily.​

Answers

Your answer is B Particle motion is coming to a complete stop.That's your answer!

Hope this helps!!!

Answer:

B

Explanation:

i have the same test

Describe how sodium (Na) and chlorine (Cl) interact to form an ionic compound. Specifically, what is happening to an electron?

Answers

When a sodium atom transfers an electron to a chlorine atom, forming a sodium cation (Na+) and a chloride anion (Cl-), both ions have complete valence shells, and are energetically more stable. The reaction is extremely exothermic, producing a bright yellow light and a great deal of heat energy.
Here you go its agin me answering you
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