Unit 3 Review

What Element has the symbol (Ar)

• Arsenic

• Astitine

• Argon

• Gold

Does not have a definite volume or shape.

• Plasma

• Gas

• Liquid

• Solid

Made up of one or more of the same kind of atom chemically combined.

• Atom

• Compound

• Element

• Mixture

The smallest unit of an element that maintains the properties of that element.

• Matter

• Law of Conservation of Mass

• Atom

• Element

A sample substance has the chemical formula: H₂CO₃

One molecule of this sample contains

• two different elements with atomic numbers 1 and 27.

• two different elements with atomic numbers 2 and 29.

• three different elements with atomic numbers 1, 6, and 8.

• three different elements with atomic numbers 2, 8, and 20.

Select two of the conclusions that best describe the diagram.

• The substances are matter made from atoms.

• The substances are molecules made from atoms.

• The substances are elements made from molecules.

• The substances are atoms made from elements.

• The substances are elements made from matter.

Espen draws an atomic model for the element neon (Ne) using information from the periodic table. How many protons and electrons does he include in his model?

• seven protons and seven electrons

• ten protons and ten electrons

• ten protons and twenty electrons

• twenty protons and twenty electrons

The most abundant element in the universe is hydrogen, which has the symbol

• H and the atomic number 1.

• He and the atomic number 2.

• Ge and the atomic number 32.

• Hg and the atomic number 80.

Carbon monoxide is a simple compound of one carbon atom and one oxygen atom. What is the sum of atomic numbers for all the elements in carbon monoxide?

• 28

• 14

• 6

• 8

Which of the following is true about the atoms and molecules in the world?

• A small, finite variety of atoms make up a nearly infinite variety of molecules.

• A nearly infinite variety of atoms make up a small, finite variety of molecules.

• A small, finite variety of atoms make up a small, finite variety of molecules.

• A nearly infinite variety of atoms make up a nearly infinite

  variety of molecules.