7th Grade School-wide Assessment Q1#2

The balanced chemical equation below shows the decomposition of water into hydrogen and oxygen gas. 2H2O(l) → O2(g) + 2H2(g) How many atoms are in the reactants?

• 2

• 4

• 6

• 8

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

The balanced chemical equation below shows the decomposition of water into hydrogen and oxygen gas. 2H2O(l) → O2(g) + 2H2(g) How many atoms are in the products?

• 2

• 4

• 6

• 8

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

Ms. Trischitta measured the mass of a closed and sealed beaker containing several ice cubes. The mass was 100g. An hour later the ice cubes had melted, and Ms. Trischitta measured the mass of the beaker again. What was the mass of the beaker?

• 25g

• 50g

• 75g

• 100g

Tags

NGSS.MS-PS1-4

NGSS.MS-PS1-5

In the chemical reaction shown, all the HCl and Zn will react to form H2 and ZnCl2. Which of the following describes the results of this reaction?

• The zinc chloride will have less mass than zinc.

• The mass of the products will equal the mass of the reactants.

• The mass of the hydrogen atoms will decrease in the products.

• The mass of the hydrogen atoms will increase in the reactants.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Consider the reaction of sodium and water below and select all the correct statements about it. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

• There are more sodium atoms in the reactants than in the products.

• There are more hydrogen atoms in the reactants than in the products.

• There are as many atoms in the reactants as there are in the products.

• Mass is conserved throughout the reaction.

• There is more hydrogen gas in the products than in the reactants.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The order of elements in the periodic table is based on

• the number of protons in the nucleus.

• the electric charge of the nucleus.

• the number of neutrons in the nucleus.

• atomic mass

As you move from left to right across the periodic table, elements

• become less metallic.

• have a lower atomic weight.

• have a lower atomic number.

• become more metallic.

Most elements are

• metals.

• metalloids.

• nonmetals.

• Semiconductors.

A mixture of two gases is in a rigid container at 25°C. The particle diagram shows a mixture of neon gas and argon gas. The temperature was decreased below the boiling point of each gas. Which diagram shows what would happen to the gas mixture?

• A

• B

• C

• D

Tags

NGSS.MS-PS1-4

Which diagram correctly represents the mass of one of the chemical reactions?

• M

• P

• R

• S

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5