Midterm Review Chemistry

Front

What is molecular polarity?

Back

Molecular polarity refers to the distribution of electrical charge over the atoms in a molecule. A molecule is polar if it has a net dipole moment due to the presence of polar bonds that do not cancel out.

Front

What particles are found inside an atomic nucleus?

Back

The nucleus of an atom contains protons and neutrons.

Front

How many valence electrons does fluorine have?

Back

Fluorine has 7 valence electrons.

Front

What is a mixture?

Back

A mixture is a combination of two or more substances where each substance retains its own properties. Example: Saltwater is a mixture of salt and water.

Front

What is the atomic mass of an element?

Back

The atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of an element.

Front

What is chromatography?

Back

Chromatography is a laboratory technique used to separate mixtures based on differences in their movement through a medium under the influence of a solvent.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance that cannot be broken down into simpler substances, while a compound is a substance formed when two or more elements chemically bond together.

Front

What is the significance of valence electrons?

Back

Valence electrons are the outermost electrons of an atom and are important for determining how an atom can bond with other atoms.

Front

What is the mass number of an isotope?

Back

The mass number of an isotope is the total number of protons and neutrons in its nucleus.

Front

What is the role of neutrons in an atom?

Back

Neutrons help stabilize the nucleus of an atom and contribute to its mass.