Midterm Chemistry 2024-2025- Mrs. Chacon

Front

In the modern periodic table, elements are arranged by:

Back

atomic number.

Front

What happens to the number of electrons when a neutral copper atom (atomic number 29) becomes an ion with a charge of 2+?

Back

It loses 2 electrons, resulting in 27 electrons.

Front

What is the correct symbol for an atom that has 33 protons, 36 electrons, and 42 neutrons?

Back

The symbol is As (Arsenic).

Front

What did Ernest Rutherford's gold foil experiment reveal about atoms?

Back

Atoms consist largely of empty space with a dense, positively charged nucleus.

Front

Which is the best example of a new substance forming?

Back

Lighting a match.

Front

What is the atomic number of an element?

Back

The number of protons in the nucleus of an atom.

Front

What is an ion?

Back

An atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

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 significance of valence electrons?

Back

Valence electrons determine how an atom can bond with other atoms.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed.