Unit One: The Atom (Chem-7)

As a result of the gold foil experiment, it was concluded that an atom

•  contains protons, neutrons, and electrons

• contains a small, dense nucleus

• has positrons and orbitals

• is a hard, indivisible sphere

An atom of any element must contain

• an equal number of protons and neutrons

  
  

• an equal number of protons and electrons

  
  

• more electrons than neutrons

• more electrons than protons

Which statement compares the masses of two

subatomic particles?

• The mass of an electron is greater than the

  mass of a proton

• The mass of an electron is greater than the

  mass of a neutron

• The mass of a proton is greater than the

  mass of an electron

• The mass of a proton is greater than the

  mass of a neutron

 Which element has an atom in the ground state with a total of three valence electrons

• aluminum

•  phosphorus

•  lithium

• scandium

 What is the mass number of a carbon atom that contains six protons, eight neutrons, and six electrons? 

• 6

• 14

• 8

• 20

What is the total number of valence electrons in an atom of germanium in the ground state?

• 8

• 2

• 14

• 4

In the wave-mechanical model of the atom, orbitals are regions of the most probable locations of

•  protons

• neutrons

• positrons

• electrons

What is the total number of electrons in an atom of potassium?

• 18

• 20

• 19

• 39

What is the total charge of the nucleus of a nitrogen atom?

• +5

• +2

• +7

• +14

Which phrase describes an atom? 

• a positively charged electron cloud surrounding a positively charged nucleus 

• a positively charged electron cloud surrounding a negatively charged nucleus

•  a negatively charged electron cloud surrounding a positively charged nucleus

•  a negatively charged electron cloud surrounding a negatively charged nucleus