4 - Radioactivity - Atoms

Question 1

What is an Atom?

Answer 1

A positively charged nucleus consisting of protons and neutrons surrounded by negatively charged electrons

Question 2

What is the typical size of an atom?

Answer 2

1 x 10^-10

Question 3

What are isotopes?

Answer 3

Atoms with the same number of Protons and Electrons but a different number of Neutrons (diff mass number)

Question 4

The nucleus of each element has a ….
but Isotopes of an element …

Answer 4

… characteristic positive charge
… differ in mass by having diff number of electrons

Question 5

Relative Mass and Relative Charge of
Protons

Answer 5

1
+1

Question 6

Relative Mass and Relative Charge of
Neutrons

Answer 6

1
0

Question 7

Relative Mass and Relative Charge of
Electrons

Answer 7

1/1840
-1

Question 8

Relative Mass and Relative Charge of
Positron

Answer 8

1/1840
+1

Question 9

In an atom, the number of protons is …

Answer 9

equal to the number of electrons ; neutral

Question 10

In each atom, the electrons …

Answer 10

orbit the nucleus at different distances

Question 11

How do electrons change orbit?

Answer 11

Excitation - if given energy they can move up a shell at higher energy

Question 12

What happens during de-excitation?

Answer 12

The energy lost by the electron is emitted as visible light
Colour of light depends on how much energy is lost by the electron

Question 13

How can an atom form a positive ion?

Question 14

What can be emitted from an unstable nucleus?

Question 15

What are alpha, β+, β- and gamma rays?

Answer 15

Ionising Radiations