Water (H₂O) and table salt (NaCl) can be combined to form salt water. How can this combination be classified?

• As a compound because the water and table salt are chemically combined
• As a compound because the water and table salt form a new pure substance
• As a mixture because the water can be evaporated and physically separated from the table salt

Which best describes an element?

• It is the simplest form of matter
• It can be changed into a compound
• It can be broken down into simpler mixtures
• It is composed of more than one type of atom

A group of science students used water, filter paper and a hot plate to separate a mixture of salt and sand. Which of the following did the students most likely do first?

• Shake the mixture until the sand settles on the bottom
• Pour the mixture through the filter paper
• Heat the mixture on the hot plate
• Dissolve the salt by adding water to the mixture

Hydrogen peroxide has one more oxygen atom than the compound water. What is the result of this extra oxygen atom?

• It makes peroxide more soluble than water
• It makes peroxide more carbonated than water
• It changes most of the properties of the compound

Tags

NGSS.MS-PS1-1

The smallest part of an element that retains the properties of the element is the

• proton
• nucleus
• electron
• atom

How many elements are in the compound sulfuric acid, H₂SO_4?

• 1
• 2
• 3

Tags

NGSS.MS-PS1-1

Which two elements make up household ammonia, NH₃?

• Neon and helium
• Neon and hydrogen
• Nitrogen and helium
• Nitrogen and hydrogen

Tags

NGSS.MS-PS1-1

When potassium and bromine atoms form chemical bonds, which of these is produced?

• An element
• A mixture
• A compound
• A new form of matter

Tags

NGSS.MS-PS1-1

What do the atomic numbers represent?

• Number of atoms
• Number of protons
• Number of neutrons

Which best explains how elements are arranged on the modern periodic table?

• Elements are arranged from fewest protons to most protons
• Elements are arranged from most protons to fewest protons
• Elements are arranged from fewest neutrons to most neutrons