Which of the following scientists’ major contribution was based on the arrangement of elements by their properties?

• Dmitri Mendeleev

• Niels Bohr

• Marie Curie

• Isaac Newton

Classify the following as either a metal, metalloid or a nonmetal:

1. Si
2. Na
3. Al

• 1: Metal 2: Non-metal 3: Metal

• 1: Metal 2: Metal 3: Metalloid

• 1: Metalloid 2: Metal 3:Metal

• 1:Non-metal 2: Non-metal 3: Non-Metal

Answer explanation

silicon is a metalloid (computer chips)

semiconductor

Which of these elements, based on the location within the periodic table, is considered a metalloid?

• blue

• green

• yellow

• don't know I'm colored blind

Mendeleev organized his periodic table in order of increasing atomic —

• mass

• number

• radius

• stability

The _ of an atom is the same as the number of protons in its nucleus.

• atomic mass

• atomic #

The _ of an element is the average mass of that element's varied isotopes.

• atomic mass

• atomic #

The _ is a chart containing information about the elements (atoms) that make up matter.

• periodic table

• atomic #

• atomic mass

• Bohr model

A(n) _ is a substance containing only one type of atom.

• element

• compound

• electron

• ion

Answer explanation

pure substance

The periodic repetition of properties of the elements, when arranged by increasing atomic number, is known as what?

• periodic law

• ionization

• atomic radii

• quadratic formula

Which of these is the correct atomic mass & atomic # for K (potassium).

• 24

  12

• 23

  11

• 40

  20

• 39

  19

Answer explanation