Atoms (T1)

Question 1

Describe electrons..

Answer 1

Tiny particles found in shells orbiting the nucleus.

The carry a negative charge but have a much smaller mass than any other particles in an atom.

The majority of the time they are never found in the nucleus and it’s the only particle outside of it.

Question 2

Explain why it is the electrons in outer shell that directly determine the chemical and physical properties of a substance..

Answer 2

Because the outer shell of an atom is the only part of an atom that can interact and bond with other atoms to form molecules.

Question 3

What is the level of energy of an electron expressed as?

Answer 3

-1

Question 4

In an atom the number of protons =

Answer 4

The number of electrons

Question 5

What is the charge of a proton expressed as?

Answer 5

+1

Question 6

Describe protons..

Answer 6

The mass of a proton is much larger than an electron.

A proton is always positive and always found in the nucleus.

Question 7

Describe neutrons..

Answer 7

Only found in the nucleus and have no charge.

Question 8

How is the charge of a neutron expressed?

Answer 8

0

Question 9

What is the mass of a proton expressed as?

Answer 9

1

Question 10

What is the mass of a neutron expressed as?

Answer 10

1

Question 11

How is the mass of an electron expressed?

Answer 11

0

Question 12

What are the particles in the nucleus of an atom called?

Answer 12

Nucleons

Question 13

What is the atomic number?

Answer 13

The number of protons in the nucleus of an atom.

Question 14

What is the mass number?

Answer 14

The number of protons and neutrons in the nucleus.

Question 15

What is an isotope?

Answer 15

Atoms of an elements that have different numbers of neutrons.

Question 16

What are the three major particles of an atom?

Answer 16

• electrons
• protons
• neutrons

Question 17

What are the electronic sub shells and the electronic capacities?

Answer 17

The shells of an atom divide sub-divide into sub shells known as s, p, d and f.

Their electronic capacities are:

s - 2
p - 6
d - 10
f - 14

Question 18

Describe Bohr’s energy levels..

Answer 18

Low energy levels: closer to nucleus
High energy levels: further from nucleus
Ground state: electron in lowest energy level possible

Question 19

What is an excited atom?

Answer 19

An atom that has absorbed energy.

The excited state is unstable.

The atom soon emits the same amount of energy absorbed.

The energy is seen as visible light.

Question 20

What is the name of the region of space where an electron is likely to be found?

Answer 20

The orbital