The nucleus of an atom

• is positively charged

• is negatively charged

• has no charged particles

• has both positively and negatively charged particles

Electrons are found

• in the nucleus

• outside the nucleus

• both in and outside the nucleus

Electrons are particles which

• have a positive charge

• have a negative charge

• have no charge

• can have either a positive or a negative charge

An atom is neutral because

• the positive charge of the nucleus is equal to the sum of the negative charges of the electrons

• the negative charge of the nucleus is equal to the sum of the positive charges of the electrons

• it does not contain any charged particles

What is the atomic number of oxygen?

• 16

• 9

• 8

• 2

What is the element with the atomic number 12?

• sodium

• iron

• bromine

• magnesium

What is the number of electrons in an atom of neon?

• 10

• 7

• 23

• 100

What is the element with 1 electron?

• helium

• hydrogen

• chlorine

• gold

Which particle has a positive charge?

• electron

• neutron

• proton

Which particle does not have a mass of 1 u?

• neutron

• electron

• proton