Science test

What is the primary organizing principle of the periodic table?

The periodic table is organized by atomic number, which corresponds to the number of protons in an atom.

How many groups and periods are in the periodic table?

There are 18 groups (columns) and 7 periods (rows) in the periodic table.

What happens to atomic mass as you move down a group in the periodic table?

Atomic mass increases as you move down a group.

What does the period number correspond to?

The period number corresponds to the number of electron shells in an atom.

What distinguishes a pure substance from a mixture?

A pure substance contains only one kind of particle, while a mixture contains two or more pure substances.

What is an element?

An element cannot be broken down into simpler substances and is made of a single type of atom.

Can compounds be physically separated?

No, compounds cannot be separated by physical means as they contain two or more different elements in a fixed proportion.

What is a homogeneous mixture?

A homogeneous mixture is a uniform mixture where the different parts cannot be seen.

What is the difference between a subscript and a coefficient in a chemical formula?

A subscript indicates the number of atoms of the element it follows, while a coefficient multiplies the entire chemical formula.

What are the three types of subatomic particles in an atom?

The three types of subatomic particles are protons (positive charge), neutrons (neutral charge), and electrons (negative charge).

What is the atomic number of an element?

The atomic number is the number of protons in an atom and determines the identity of the element.

If an atom is neutral, what is the relationship between protons and electrons?

In a neutral atom, the number of protons equals the number of electrons.

How do you calculate the mass number of an atom?

The mass number is calculated by adding the number of protons and neutrons.