P7 Atoms

Question 1

describe basic structure of an atom

Answer 1

nucleus contains protons and neutrons
electrons that orbit in fixed energy shells

Question 2

Describe the plum pudding model of atom.

Answer 2

sphere of positive charge with negative electrons embedded in it

Question 3

why do atoms overall have no charge

Answer 3

equal number of protons and electrons

Question 4

What is the radius of an atom?

Answer 4

1 x 10^-10 m

Question 5

how can an electron move up an energy level

Answer 5

Absorb sufficient electromagnetic radiation

Question 6

what is ionisation

Answer 6

process which adds or removes electrons from an atom

Question 7

what is the atomic number of an element

Answer 7

number of protons

…in one atom of the element

Question 8

what is the mass number of an element

Answer 8

no. of protons + no. of neutrons

Question 9

2 main conclusions from the alpha particle scattering experiment

Answer 9

most of mass of an atom is concentrated in nucleus

nucleus is positively charged

Question 10

what would cause light to be emmitted from a sodium atom?

Answer 10

electron FALLING to a lower energy level