HChem Midterm Practice

Front

What does an atom's atomic number represent?

Back

The atomic number represents the number of protons in an atom.

Front

What type of ion is an anion?

Back

An anion is a negative ion.

Front

Who is credited with creating the first periodic table based on atomic mass?

Back

Dmitri Mendeleev.

Front

What is the empirical formula for a compound consisting of 72.2% magnesium (Mg) and 27.8% nitrogen (N) by mass?

Back

Mg3N2.

Front

Which of the following is an example of a physical change?

Back

Crushing a can.

Front

Define an atom.

Back

An atom is the smallest unit of matter that retains the properties of an element.

Front

What is a cation?

Back

A cation is a positively charged ion.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.

Front

What is the law of conservation of mass?

Back

The law states that mass is neither created nor destroyed in a chemical reaction.

Front

What is a chemical change?

Back

A chemical change results in the formation of new substances with different properties.