Chemistry chapter 3

Mendeleev created the first periodic table by arranging elements in order of

• decreasing atomic mass.

• increasing atomic mass.

• increasing atomic number.

• increasing melting points and densities.

How did chemists change Mendeleev’s periodic table in the early 1900s?

• They included chemical properties such as bonding power.

• They included physical properties such as melting point and density.

• They used atomic mass instead of atomic number to organize the elements.

• They used atomic number instead of atomic mass to organize the elements.

From an element’s location in the periodic table, you can predict

• its properties.

• its chemical name.

• its chemical symbol.

• when it was discovered.

Because atoms are so small,

• scientists create models to describe them.

• they cannot be made of smaller particles.

• there is no way to describe them.

• they cannot be synthesized by scientists.

Tags

NGSS.MS-PS1-1

In the periodic table, the most reactive metals are found

• in Group 1, the first column on the left.

• in Period 1, the first row across the top.

• in Groups 13 through 16 in the center.

• in Periods 6 and 7 at the bottom.

In an atom, the number of protons equals the number of

• nuclei.

• electrons.

• neutrons.

• isotopes.

The elements in a row of the periodic table

• are in the same family.

• have the same or nearly the same properties.

• have the same average atomic mass.

• have properties that change in a pattern.

The elements in a column of the periodic table

• have similar properties.

• are in the same period.

• have the same atomic mass.

• have very similar chemical symbols.

What information in the periodic table indicates the number of protons in an atom?

• the position of the element in its column

• the element’s chemical symbol

• the element’s atomic number

• the element’s atomic mass

Which parts of the atom move around the nucleus?

• atomic mass units

• electrons

• protons

• neutrons