Atoms-Formulas-Evidence of Chem Reaction

Which of the following chemical formulas contains exactly 4 hydrogen atoms?

• CH₃COONa

• NH₄OH

• CH₃CH₂Cl

• CH₃CHO

Tags

NGSS.MS-PS1-1

How many atoms of carbon are in the formula CH₃CH₂CH₂OH?

• 3

• 1

• 7

• 4

Tags

NGSS.MS-PS1-1

How many atoms of hydrogen are in the formula CH₃CH₂Br?

• 5

• 3

• 2

• 7

Tags

NGSS.MS-PS1-1

Which of the following accurately describes the chemical formula of the molecule shown above?

• 3CH₈O

• C₃H₇O

• C₄H₈O₂

• C₃H₈O

Tags

NGSS.MS-PS1-1

A clear liquid from a flask is poured into another clear liquid in a beaker. Which of the following results of this procedure would indicate a new substance was formed?

• The level of the substance in the beaker is higher after the other liquid is added.
• A yellow solid forms and then settles to the bottom of the beaker.
• Small white crystals are left behind in the flask that held the first liquid.

Tags

NGSS.MS-PS1-2

Which of the following is an example that includes evidence of a chemical reaction?

• A sample of zinc is placed in water and it settles to the bottom
• A solid block of ice is heated and it completely melts into a liquid. 
• Sugar that is burned gives off an odor and turns brown and then black.
• A tomato is placed into a blender and chopped up into smaller pieces.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is NOT evidence that that a chemical reaction has occurred?

• produces light/heat
• production of a gas
• formation of a precipitate
• melting

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

1. Serotonin is a chemical substance that acts as a neurotransmitter. It helps relay messages in the human brain. The formula for one molecule of serotonin is shown below.

C₁₀H₁₂N₂O

How many atoms in all are in a molecule of serotonin?

• 24

• 22

• 25

• 23

Tags

NGSS.MS-PS1-1

Sodium has an atomic number of 11, how many protons does this atom have?

• 22
• 11
• 12
• 2

Tags

NGSS.MS-PS1-1

What element contains 26 protons?

• Iron
• Sodium
• Aluminum
• Helium