[22 Aug] S1: Atoms & Molecules I

Which of the following contributes the least to the mass of an atom?

• electron

• neutron

• nucleus

• proton

Which of the following is true about the structure of an atom?

• Negatively charged subatomic particles are tightly packed together in the centre of an atom.

• Neutrons can be found in the electron shells.

• Positively charged subatomic particles move rapidly around the nucleus.

• The nucleus does not contain any electrons.

Which of the following statements explains why atoms are electrically neutral?

• The number of protons in an atom is the same as its nucleon number.

• The number of protons in an atom is the same as its relative atomic number.

• The number of protons in an atom is the same as the number of electrons.

• The number of protons in an atom is the same as the number of neutrons.

The diagram shows the electronic structure of an atom.

What is the chemical symbol of this element?
(Hint: Refer to the Periodic Table.)

• Al

• P

• S

• Si

The diagram shows the nuclide notation of an element.

What is the name of this element? [1]

Answer explanation

The diagram shows the nuclide notation of an element.

State the mass number of the element. [1]

Answer explanation

The diagram shows the nuclide notation of an element.

State the proton number of the element. [1]

Answer explanation

The diagram shows the nuclide notation of an element.

State the number of neutrons in one atom of the element. [1]

Answer explanation