Year 10 End of Year Quiz

The nucleus of an atom is...

• Negatively charged

• Neutral in charge

• Positively charged

• Doesn't have a charge

Answer explanation

Only the protons and neutrons exist in the nucleus, the protons are positively charged, the neutrons are neutral. So overall the charge is positive.

The mass is concentrated in the ________ of the atom

Answer explanation

The protons and neutrons are the only particles in the atom that contribute to the mass. Both have a relative mass of 1.

An atom has an atomic number of 10 and an atomic mass of 20. How many protons does this atom have?

• 10

• 20

• 30

• 25

Answer explanation

The number of protons is determined by the atomic number.

Circle the particle that represents a neutron

Answer explanation

The green particle is the neutron as it does not have a charge (+/-), this is because it is neutral in charge.

An atom has an atomic number of 19 and a mass number of 39. How many neutrons does the atom have?

• 19

• 39

• 20

• 58

Answer explanation

The number of neutrons is the difference between the atomic number and the mass number.

A radioactive isotope has an activity of 100Bq, after 80 years, this activity has changed to 25Bq. What is the half-life of this isotope?

• 80 years

• 25 years

• 120 years

• 40 years

Answer explanation

The activity (100) has halved twice (to 25) in 80 years. It would take only 40 years to half once. This is the half-life.

An alpha particle is made up of

• 2 protons and 4 neutrons

• 1 proton and 1 neutron

• 2 protons and 2 neutrons

• 4 protons and 2 neutrons

Which type of nuclear radiation can be stopped 60 cm of aluminum or 7 cm of lead?

• Alpha

• Beta

• Gamma

A radioactive shoe is wrapped in 3mm of aluminum foil but radiation is still detected. What must be true?

• The shoe emits alpha radiation

• The shoe emits beta radiation

• The shoe emits gamma radiation

What will the values of x and y be?

• x=194, y =83

• x=194, y =84

• x=194, y =85

• I don't know. I should probably study this stuff more before the test.