LS 1st Sem Test

Front

Who arranged the periodic table of elements by the atomic mass?

Back

Dmitri Mendeleev

Front

What is a substance made of 2 or more elements that are chemically combined in a set ratio?

Back

Compound

Front

Atoms tend to be stable and nonreactive if they have how many valence electrons?

Back

8

Front

What do atoms of the same periodic group have in common?

Back

They have similar chemical properties.

Front

In the periodic table, how do the number of valence electrons change from left to right across each period?

Back

Increases

Front

What is the smallest unit of an element that retains the properties of that element?

Back

Atom

Front

What is a mixture?

Back

A combination of two or more substances that are not chemically combined.

Front

What is the atomic number of an element?

Back

The number of protons in the nucleus of an atom.

Front

What is a chemical bond?

Back

A force that holds atoms together in a compound.

Front

What are the three main types of chemical bonds?

Back

Ionic, covalent, and metallic bonds.