Physics: Describing Atoms

Question 1

What are the three main subatomic particles of an atom?

Answer 1

Protons, neutrons, electrons

These particles make up the structure of an atom.

Question 2

What is the radius of an atom?

Answer 2

Around 1×10^-10 metres

Atoms are incredibly small.

Question 3

What is the charge of the nucleus of an atom?

Answer 3

Positively charged

The nucleus contains protons and neutrons.

Question 4

Where are electrons located in an atom?

Answer 4

Orbiting outside the nucleus

Electrons are much smaller than protons and neutrons.

Question 5

What particles are found in the nucleus of an atom?

Answer 5

Protons and neutrons

The nucleus is the central part of the atom.

Question 6

What charge do protons have?

Answer 6

Positive charge

Protons are one of the key components of the atomic nucleus.

Question 7

What is the charge of neutrons?

Answer 7

No charge (neutral)

Neutrons contribute to the mass of the nucleus but not to its charge.

Question 8

What charge do electrons have?

Answer 8

Negative charge

Electrons are responsible for chemical bonding.

Question 9

Fill in the blank: Each particle of an atom has its own ______ and its own mass.

Answer 9

charge

This distinguishes the different subatomic particles.

Question 10

What charge does a proton have?

Answer 10

+1

Question 11

What is the relative mass of a proton?

Answer 11

1

Question 12

What charge does a neutron have?

Answer 12

0

Question 13

What is the relative mass of a neutron?

Answer 13

1

Question 14

What charge does an electron have?

Answer 14

-1

Question 15

What is the relative mass of an electron?

Answer 15

1/1835

Question 16

What particles make up most of the mass of an atom?

Answer 16

Protons and neutrons

Question 17

What defines the element of an atom?

Answer 17

The number of protons

Question 18

What is the mass number?

Answer 18

The total number of protons and neutrons

Question 19

What is the atomic number?

Answer 19

The number of protons

Question 20

What is another name for mass number?

Answer 20

‘Nucleon number’

Mass number can also be called ‘nucleon number’.

Question 21

What is another name for atomic number?

Answer 21

‘Proton number’

Atomic number can also be called ‘proton number’.

Question 22

In a neutral atom, how do the number of electrons and protons compare?

Answer 22

They are always the same.

Question 23

What happens to the number of electrons in an ion?

Answer 23

It changes; an ion has lost or gained one or more electrons.

Question 24

What did most people in ancient Greece believe matter was made of?

Answer 24

Most people believed matter was made up of combinations of four elements: earth, air, fire, and water.

Question 25

Who was the ancient Greek philosopher that proposed the idea of uncuttable pieces of matter?

Answer 25

The philosopher Demokritos (460-370 BCE) thought that matter was made up of millions of tiny, uncuttable pieces.

Question 26

What does the word ‘atom’ mean?

Answer 26

The word ‘atom’ comes from the word ‘atomos’, which means uncuttable.

Question 27

What are isotopes?

Answer 27

Isotopes are forms of an element that have the same number of protons but different numbers of neutrons.

Question 28

What are three ways to give electrons energy?

Answer 28

Light, Electricity, Heat

Question 29

What happens if an electron absorbs lots of energy?

Answer 29

If an electron absorbs enough energy, it can leave the atom completely. This makes the atom an ion.

Question 30

What happens when atoms absorb energy?

Answer 30

Electrons at a particular level are pushed up to higher levels, becoming ‘excited’.

Question 31

What occurs after electrons become excited?

Answer 31

They eventually jump back down to a lower level, releasing the energy as an electromagnetic wave