Atomic Structure & Periodic Table

Question 1

What is the atomic number

Answer 1

Atomic number is the number of protons + electrons in the atom

Question 2

What is the mass number of an atom

Answer 2

The mass is the total number of particles in the atom

Mass number = no. Of protons + no. Of electrons

Question 3

How does the number of valence electrons in an atom affect where it is on the periodic table

Answer 3

The number of valence electrons in an atom determines what group (column) it’s in on the periodic table

Question 4

What are the characteristics of metals and where are they found on the periodic table

Answer 4

Metals are shiny/silvery, solid, malleable and good conductors
They are found from the right to the middle of the periodic table

Question 5

What does radioisotopes mean

Answer 5

It’s an atom with an unstable nucleus the will decay and emit radiation until it becomes stable

Question 6

What are the characteristics of alpha radiation

Answer 6

• 2 protons + 2 neutrons
• 2+ charge
• has a range of a few cms in the air
• can not penetrate skin
• is stopped by paper, skin or cloth

Question 7

What are the characteristics of beta radiation

Answer 7

• high energy electrons
• -1 charge
• has a range of a few ms in the air
• can penetrate skin by a few mm
• can be stopped by wood or metal sheets

Question 8

What are the characteristics of gamma radiation

Answer 8

• electromagnetic radiation (pure energy)
• no charge
• range in air is 100s of ms
• goes right through body
• think lead or concrete can stop it

Question 9

What are the effects of radiation on a cell

Answer 9

Direct radiation can cause irrepairable damage to the cell and it can die, it can also cause mutations in the cell DNA which can lead to cancer
Indirect radiation can cause new reactive and dangerous molecules in the cell

Question 10

What does half life mean

Answer 10

It’s the length of time it takes for a radioisotope to decay half of the mass of the substance