Chemistry - atoms, periodic table

Front

What is the atomic number?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

Which group of metals is the most reactive?

Back

The most reactive metals are the alkali metals, found in Group 1 of the periodic table.

Front

What are valence electrons?

Back

Valence electrons are the electrons located in the outermost energy level of an atom, which are involved in chemical bonding.

Front

What is an atom?

Back

An atom is the basic building block of all matter, consisting of protons, neutrons, and electrons.

Front

What are groups in the periodic table?

Back

Groups are vertical columns in the periodic table where elements have similar chemical properties.

Front

What is a period in the periodic table?

Back

A period is a horizontal row in the periodic table, indicating the number of electron shells in the elements.

Front

What is the mass number?

Back

The mass number is the total number of protons and neutrons in an atom's nucleus.

Front

What are noble gases?

Back

Noble gases are elements in Group 18 of the periodic table, known for their lack of reactivity due to having a full outer electron shell.

Front

What are halogens?

Back

Halogens are highly reactive nonmetals found in Group 17 of the periodic table.

Front

What is the difference between atomic mass and mass number?

Back

Atomic mass is the weighted average mass of an element's isotopes, while mass number is the total count of protons and neutrons in a specific isotope.