Unit 1.2 Basic Ideas about Atoms (pt. 1 Atomic Structure)

Question 1

Describe the structure of an atom.

Answer 1

All atoms contain a central nucleus which contains the atom’s protons and neutrons.

Around the nucleus are the atom’s electrons, located in energy levels.

Question 2

What is the proton number?

Answer 2

The number of protons is the proton number or the atomic number of the element

Question 3

How do you calculate the number of neutrons?

Answer 3

mass number - atomic number

Question 4

What is the mass of a proton?

Answer 4

1.673 x 10^-27 kg

Question 5

What is the relative mass of a proton?

Answer 5

1

Question 6

What is the relative charge of a proton?

Answer 6

+1

Question 7

What is the mass of a neutron?

Answer 7

1.675 x 10^-27kg

Question 8

What is the relative mass of a neutron?

Answer 8

1

Question 9

What is the relative charge of a neutron?

Answer 9

0

Question 10

What is the mass of an electron?

Answer 10

9.109 x 10^-31kg

Question 11

What is the relative mass of an electron?

Answer 11

0.00055

Question 12

What is the relative charge of an electron?

Answer 12

-1

Question 13

Define relative atomic mass.

Answer 13

The average mass of one atom of that element relative to 1/12th the mass of an atom of carbon-12

Question 14

Why is the mass number on the periodic table known as the relative atomic mass?

Answer 14

Since most elements occur naturally as two or more different isotopes, the mass number reported on the periodic table is the relative atomic mass.

Question 15

What are isotopes?

Answer 15

Isotopes are atoms of the same element which have the same number of protons, but different numbers of neutrons.

Question 16

How are specific isotopes named?

Answer 16

Specific isotopes are named using their mass numbers appended to the element name, for example, chlorine -35 and chlorine -37.

Question 17

Does the nucleus of an atom change during a chemical reaction?

Answer 17

In chemical reactions, electrons can be lost or gained to form ionic compounds or shared with other atoms to form covalent bonds.

However, in these reactions, there are no changes to the nucleus of any atom - the number of protons and neutrons remain the same.

Question 18

When does the nucleus of an atom change?

Answer 18

During nuclear reactions involving radioactive decay.

In these types of reactions, both the numbers of protons and neutrons in the nucleus can change - causing a change in element and a change in mass.