PRE-UPS 1

Which state of matter has particles that are tightly packed?

• Gas
• Solid
• Liquid
• All of the above

Aluminium chloride, AlCl₃ exists as

• Atom
• Electron
• Ion
• Molecule

Which of the following substances is NOT an element?

• Cu
• Ca
• Cl
• CO₂

Water vapour cooling and turns into water droplets is an example of

• Condensation
• Evaporation
• Freezing
• Melting

Isotopes are atoms of an element that

• have the same atomic number.
• different mass number but have the same proton number.
• has the same number of neutrons.
• different nucleon number but has the same mass number.

The number of electrons in ⁶³₂₉Cu are

• 28
• 29
• 62
• 63

Table 1 below shows the number of protons and neutrons of four different atoms. Which atoms are isotope?

• A and B
• B and D
• C and D
• B and C

An element X has 10 electrons and 10 neutrons. What is the nucleon number of this element?

• 18
• 19
• 20
• 21

The relative molecular mass is the mass of a molecule of a compound compared to

• the mass of a carbon-12 atom
• the mass of a hydrogen atom
• one twelfth the mass of a carbon-12 atom
• one twelfth the mass of a hydrogen atom

What is the correct name for this polyatomic ion, ClO⁻

• chlorite
• chlorate
• perchlorate
• hypochlorite