Structure of the Atom

Which sub-atomic particle has a relative charge of -1?

(a)  

Which sub-atomic particles have a relative mass of 1?

• proton

• electron

• neutron

What is the relative charge of a neutron?

(a)  

The overall charge of any atom is zero because all atoms have an equal number of positive protons and negative (a)   .

All atoms of the same element have the same number of (a)   in the nucleus.

What is the approximate radius of an atom?

• 1x10^-5 m

• 1x10^-10 m

• 1x10^-15 m

• 1x10^-20 m

What is the approximate radius of a nucleus?

• 1x10^-11 m

• 1x10^-12 m

• 1x10^-13 m

• 1x10^-14 m

The mass number gives the number of __________ in the atom.

• protons and neutrons

• protons and electrons

• electrons and neutrons

• neutrons

What is the mass number of sodium?

(a)  

What is the atomic number of helium?

(a)