Elements, Compounds, and molecules

Hydrogen is a pure substance represented by the chemical symbol H. Which of the following best describes hydrogen?

• Hydrogen is an element made of two or more kinds of atoms.
• Hydrogen is a compound made of only one kind of atom.
• Hydrogen is a compound made of two or more kinds of atoms.
• Hydrogen is an element made of only one kind of atom.

The element oxygen, represented by the symbol O, is classified as

• a pure substance
• a compound
• a mixture
• a solution

Tags

NGSS.MS-PS1-1

What is a compound?

• an atom with more electrons than protons
• a substance in which the atoms of two or more elements are combined together
• an atom with more neutrons than protons
• a substance in which the atoms of three or more elements are combined together

Tags

NGSS.MS-PS1-1

The chemical combination of two or more different kinds of atoms in fixed amounts is called a(n)

• orbit
• compound
• mixture
• element

Tags

NGSS.MS-PS1-1

Atoms combine to form _______. 

• electrons
• molecules
• nuclei
• neutrons

Tags

NGSS.MS-PS1-1

Carbon dioxide is formed when two oxygen atoms chemically combine with a carbon atom. Which term best describes carbon dioxide?

• atom
• mixture
• element
• compound

Tags

NGSS.MS-PS1-1

What defines a mixture?

• described by a chemical formula
• can be broken down into its basic substances through physical means
• created through a chemical reaction
• cannot be broken down into simpler substances

What is the tiniest particle in the entire universe?

• cells
• gases
• atoms
• liquids

Tags

NGSS.MS-PS1-1

What is the name of a single type of atom?

• cell
• proton
• element
• atom

What is the term for combining 2 or more atoms together?

• atoms
• elements
• molecules
• compounds

Tags

NGSS.MS-PS1-1