8th Chemistry STAAR 2016

An atom of a certain element has 36 protons, 36 electrons, and a mass number of 84. At room temperature this element is a very stable gas. How many neutrons are in the atom?

• 48
• 36
• 84
• -36

Tags

NGSS.MS-PS1-1

• A
• B
• C
• D

Tags

NGSS.MS-PS1-1

• A
• B
• C
• D

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

• A
• B
• C
• D

Which information could a student determine from only the chemical formula of a protein?

• The color of the protein
• The number of molecules in each sequence that makes up a protein
• The physical arrangement of atoms in the structure of the protein
• The number of atoms of each element in the protein

Hay is made up of organic compounds. What are the main elements in many organic compounds?

• Helium, Carbon, Sodium
• Sodium, Hydrogen, Nitrogen
• Carbon, Hydrogen, Oxygen
• Radon, Oxygen, Helium

Tags

NGSS.HS-LS1-6

5 Which of the following best describes an electron?

• It has no charge and about the same mass as a proton.
• It has a negative charge and much less mass than a proton.
• It has a positive charge and much more mass than a neutron.
• It has a negative charge and about the same mass as a neutron.

When trying to identify an unknown element, a scientist determines what other elements the unknown element reacts with chemically. Which property of the unknown element determines the other elements it reacts with?

• The total number of neutrons in the unknown element
• The total number of particles in the nucleus of the unknown element
• The number of protons in the nucleus of the unknown element
• The number of valence electrons in the unknown element

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

**

• 1
• 2
• 3
• 4

Tags

NGSS.HS-PS1-1

An atom has 25 protons, 30 neutrons, and 25 electrons. What is the charge of the atom’s nucleus?

• +25
• +30
• -25
• -30