LHTB Physics Pre-Exam (2.1 Matter)

An atom with 3 free electrons in its outer shell is said to be

• trivalent

• covalent

• pentavelent

What is the mass number of an element?

• Number of neutrons and protons

• Number of protons

• Number of electrons

What do you get when you add 2H2 and O?

• 2H2O

• H2 O2

• H2OH2

The splitting of a chemical compound is called

• synthesis

• analysis

• bombardment

What is the atomic number of an element?

• The number of protons in the atom

• The number of electrons in the atom

• The number of neutrons in the atom

An atom with 5 free electrons is said to be

• Trivalent

• Covalent

• Pentavalent

An atom consists of

• protons, neutron and electrons

• protons and neutrons

• neutrons

The maximum number of electrons in the inner shell of an atom is

• 8

• 6

• 2

The mass of a proton equals the mass of a

• neutron

• electron

• beta particle

Catalysts…

• speed up reactions

• slow down reactions

• speed up and slow down reactions