Mr Davies Exam

Question 1

How many electrons does a Ca2+ have?

Ca has 20 electrons

Answer 1

How many electrons does a Ca2+ have?

18

Question 2

Give the relative masses of the particles in an atom

Protons =

Electrons =

Neutrons =

Answer 2

Give the relative masses of the particles in an atom

Protons = 1

Electrons = 1/2000

Neutrons = 1

Question 3

Mass number

Answer 3

Number of protons and neutrons in the nucleus

Question 4

Isotopes are ..

Answer 4

Atoms with same number of protons but a different number of neutrons

Question 5

Why isotopes have same chemical properties

Answer 5

An elements chemical properties are decided by its electron configuration. Isotopes have the same electron configuration

Question 6

Why do isotopes can have different physical properties

Answer 6

Physical properties are dependent on the mass of the atom. Isotopes have different masses. So they have different physical properties

Question 7

How was JJ Thompson’s model of the atom different from daltons model

Dalton described atoms as solid spheres JJ Thompson suggested that atoms were not solid spheres
he thought they contain small negatively charged particles in a positively charged pudding

Answer 7

How was JJ Thompson’s model of the atom different from daltons model

Dalton described atoms as solid spheres JJ Thompson suggested that atoms were not solid spheres
he thought they contain small negatively charged particles in a positively charged pudding

Question 8

Explain how Rutherford’s gold foil experiment provided evidence that Thompson’s model was wrong

Answer 8

Explain how Rutherford’s gold foil experiment provided evidence that Thompson’s model was wrong