Review for Chem Fall Sem Exam 2024

Front

What type of bond has unequal attraction due to electrons being held more closely by one atom?

Back

Polar covalent bond.

Front

How many electrons are shared in a double covalent bond?

Back

Four electrons.

Front

What is the mass number of a gold isotope with 79 protons and 123 neutrons?

Back

197.

Front

What conclusion did Rutherford reach when most alpha particles passed through metal foil?

Back

Atoms are mostly empty space.

Front

According to VSEPR theory, what is the shape of a molecule of NBr₃?

Back

Trigonal-pyramidal.

Front

Define a polar covalent bond.

Back

A bond where electrons are shared unequally between two atoms.

Front

What is the definition of a double covalent bond?

Back

A bond involving the sharing of two pairs of electrons (four electrons total).

Front

How do you calculate the mass number of an atom?

Back

Mass number = number of protons + number of neutrons.

Front

What did Rutherford's gold foil experiment demonstrate about atomic structure?

Back

It demonstrated that atoms have a small, dense nucleus and are mostly empty space.

Front

What is VSEPR theory used for?

Back

To predict the shape of molecules based on the repulsion between electron pairs.