MDCAT Chemistry MCQs

An anion forms when electrons are gained.
It has more electrons than protons.

Electronegativity helps predict bond polarity.
Fluorine has the highest common electronegativity.

Rutherford concluded that atoms contain a small dense positive nucleus.
Most atomic volume is empty space.

Valence electrons largely determine chemical reactivity.
Elements in a group often share similar valence configurations.

Molarity equals moles divided by liters of solution.
0.50/2.0 = 0.25 M.

Atomic number identifies the element.
In a neutral atom it also equals the number of electrons.

Mass number applies to a specific isotope.
It is always a whole number.

Isotopes have the same atomic number but different mass numbers.
Their chemical behavior is usually similar.

Ions form by gaining or losing electrons.
Cations are positive and anions are negative.

A cation forms when electrons are lost.
It has more protons than electrons.

Mass equals moles multiplied by molar mass.
2×58.5 = 117 g.

Particles equal moles times Avogadro's number.
0.5×6.022×10^23 = 3.011×10^23 molecules.