Chemistry Semester 1 Exam 2022

The nucleus of an atom is made of

• electrons and protons
• electrons and neutrons
• protons and neutrons
• empty space

Which of these phrases best describes an atom?

• a positive nucleus surrounded by a hard negative shell
• a positive nucleus surrounded by a cloud of negative charges
• a hard sphere with postive and negative charges on the outside
• a negative nucleus surrounded by protons and neutrons

What scientist is best known for his gold foil experiment?

• J.J. Tomson
• Ernest Rutherford
• John Dalton
• Democritus

Who is the first scientist to think that the atom was the smallest unit of matter?

• J.J. Tomson
• Ernest Rutherford
• John Dalton
• Democritus

What scientist first developed 5 rules for atomic theory, and helped kick start modern chemistry?

• J.J. Tomson
• Ernest Rutherford
• John Dalton
• Democritus

In order for an atom to be neutral what has to be true?

• The atom has more protons than neutrons
• The atom has more neutrons than protons
• The atom has the same number of protons and neutrons
• The atom has the same number of protons and electrons

Isotopes of an element have a different number of...

• Protons

• Neutrons

• Electrons

• Mass

On the periodic table, how is atomic mass represented?

• As an average of the mass of different isotopes
• as the exact mass of every atom
• as the mass of the most common isotopes
• As the masses of all protons added together

What do carbon-12 and carbon-14 have in common?

• they have same number of protons
• they have the same number of neutrons
• they have the same atomic mass
• they have the same atomic weight

How is carbon-12 different from carbon-14?

• They have a different number of protons
• they have a different number of electrons
• they have a different number of neutrons
• they are different elements