7th Grade Midterm 23-24

The image shows two different atomic models made by two students. What can be concluded about the models?

• Both models are accurate because they show protons and electrons inside the nucleus.

• Model 1 is accurate because the numbers of protons and electrons inside the atom are the same.

• Both models are accurate because they contain positively charged protons and negatively charged electrons.

• Model 2 is accurate because it shows protons and neutrons at the center of the atom and electrons in orbits around the center.

Tags

NGSS.MS-PS1-1

An atom of chlorine has an atomic number of 17 and an atomic mass of 35. How many protons and neutrons are in the atom?

• 17 protons and 17 neutrons

• 17 protons and 18 neutrons

• 18 protons and 17 neutrons

• 18 protons and 18 neutrons

Tags

NGSS.MS-PS1-1

A student is writing a formula for a compound. What must the student always remember to include?

• at least one number written low as a subscript

• at least two capital letters

• at least two lowercase letters

• at least one number written large as a coefficient

The atmosphere is made of several gases including nitrogen (N2), oxygen (O2), argon (Ar), and carbon dioxide (CO2). How can the gases in Earth’s atmosphere be described?

• monoatomic and diatomic elements only

• diatomic elements and compounds only

• monoatomic elements and compounds only

• monoatomic and diatomic elements, and compounds

Tags

NGSS.MS-PS1-1

How is an elemental molecule different from a compound molecule?

• An elemental molecule contains only one atom of one element, while a compound molecule contains two or more atoms of the same element.

• An elemental molecule contains only one atom of one element, while a compound molecule contains atoms of two or more different elements.

• An elemental molecule contains two or more atoms of the same element, while a compound molecule contains atoms of two or more different elements.

• An elemental molecule contains atoms of two different elements, while a compound molecule contains two or more atoms of the same element.

Tags

NGSS.MS-PS1-1

A student packs a salad for lunch. How can the salad be classified?

• compound

• element

• heterogeneous mixture

• homogeneous mixture

The diagram represents a sample of matter. How is the sample of matter best classified?

• compound

• diatomic element

• mixture

• monoatomic element

Tags

NGSS.MS-PS1-1

Which type(s) of matter is (are) considered a pure substance?

• compounds and mixtures

• elements only

• elements and compounds

• mixtures only

Which term is missing as indicated by the "?" in the diagram below?

• atom

• compound

• metals

• molecules

Tags

NGSS.MS-PS1-1

Examine the balanced chemical reaction. Which answer represents the numbers of carbon, oxygen, and hydrogen atoms that are present on both sides of the balanced chemical reaction?

• C-2

  O-5

  H-10

• C-4

  O-5

  H-6

• C-3

  O-10

  H-8

• C-6

  O-10

  H-2

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5