CHAPTER 2 -Grade 7 - Foundations of Chemistry

The formula AgNO3 represents a compound made of which atoms?

• 1 Ag, 1 N, 3 O

• 1 Ag, 1 N, 1 O

• 1 Ag, 3 N, 3 O

• 3 Ag, 3 N, 3 O

Tags

NGSS.MS-PS1-1

Which is an example of an element?

• air

• water

• sugar

• sodium

Which property explains why copper often is used in electrical wiring?

• density

• magnetism

• conductivity

• . solubility

Tags

NGSS.MS-PS2-3

For which substance would a 4.90-g sample have a volume of 3.10 cm3 ?

• $d=\frac{m}{v}$ . substance 2

• $d=\frac{m}{v}$ . substance 1

• $d=\frac{m}{v}$ substance 4

• $d=\frac{m}{v}$ . substance 3

Tags

NGSS.MS-PS1-2

Which would decrease the rate of a chemical reaction?

• decrease in surface area

• increase in concentration

• increase in temperature

• increase in both surface area and concentration

Which physical change is represented by the diagram below?

• evaporation

• condensation

• sublimation

• deposition

Tags

NGSS.MS-PS1-4

Which chemical equation is unbalanced?

• Fe2O3 + CO → 2Fe + 2CO2

• 2KClO3 → 2KCl + 3O2

• CH4 + 2O2 → CO2 + 2H2O

• H2CO3 → H2O + CO2

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

. Which is a size-dependent property?

• boiling point

• conductivity

• density

• mass

Tags

NGSS.MS-PS2-2

Why is the following chemical equation said to be balanced?

O2 + 2PCl3 → 2POCl3

• There are more reactants than products

• There are more products than reactants.

• . The atoms are the same on both sides of the equation

• The coefficients are the same on both sides of the equation.

Tags

NGSS.MS-PS1-5

The elements sodium (Na) and chlorine (Cl) react and form the compound sodium chloride (NaCl). Which is true about the properties of these substances?

• Na and Cl have the same properties.

• NaCl has the properties of Na and Cl

• All the substances have the same properties.

• The properties of NaCl are different from the properties of Na and Cl.

Tags

NGSS.MS-PS1-2