Unit B (Matter: Properties and Changes)

Which of these determines the identity of an element?

• number of protons

• number of electrons

• number of energy levels

• number of neutrons

Sodium is an element found in table salt. It contains 11 protons and 12 neutrons. How many electrons are found in a neutral atom of sodium?

• 11

• 23

• 12

• 1

Tags

NGSS.MS-PS1-1

What is formed when two or more elements are chemically combined?

• atom

• composite

• compound

• mixture

Tags

NGSS.MS-PS1-1

Elements are described as pure substances because

• they are found in nature.

• they cannot be separated into parts by physical means.

• they have no charge.

• they can be produced in a laboratory.

The nucleus of an atom contains

• only neutrons

• protons and electrons

• protons and neutrons

• only electrons

How are the elements in the modern periodic table arranged?

• alphabetical order

• by atomic mass

• by date discovery

• by number of protons

Which elements in the periodic table are least likely to combine with other elements?

• halogens

• noble gases

• alkaline earths

• transition metals

Carbon and oxygen combine chemically to form carbon dioxide. Carbon dioxide is

• an ion

• a nucleus

• a compound

• an atom

Tags

NGSS.MS-PS1-1

Which of these is not made up of two or more substances that are combined physically?

• homogeneous mixture

• compound

• heterogeneous mixture

• solution

Filtration can be used to separate a mixture of

• a solid and a liquid

• a liquid and a gas

• two liquids

• two solids