quiz 1

Which of the following is true of a mixture? A. A mixture is a combination of two or more substances in which the substances retain their distinct identities. B. A mixture is a substance that cannot be separated into simpler substances by chemical means. C. A mixture is a substance composed of atoms of two or more elements D. A mixture must be homogeneous E. A mixture must be heterogeneous

A. A mixture is a combination of two or more substances in which the substances retain their distinct identities.

All of the following are properties of sodium. Which one is a physical property of sodium? A. It's surface turns black when first exposed to air. B. It is a solid at 25C and changes to a liquid when heated to 98C. C. When placed in water it sizzles and a gas is formed. D. When placed in contact with chlorine it forms a compound that melts at 801C. E. Sodium is never found as the pure metal in nature.

B. It is a solid at 25C and changes to a liquid when heated to 98C.

Select True or False: The mass of a body varies according to the force of gravity exerted on the body.

False

Conversion from C to F

C * 1.8 + 32 = F

How many significant figures are there in 0.3070 g? A. 6 B. 5 C. 4 D. 3 E. 2

C. 4

Which one of the following represents a chemical change? A. boiling water to form steam B. mixing iron filings and sand at room temperature C. burning a piece of coal D.breaking glass E. heating lead until it melts

C. burning a piece of coal

To solve for Mass

Density * Volume

Which of the following is an accurate definition of a pure substance? A. A pure substance must be made of only one element B. A pure substance must be a solid at room temperature C. A pure substance will be transparent E.2.6min D. A pure substance is matter that cannot be broken down into other matter E. A pure substance is matter that has a definite composition

E. A pure substance is matter that has a definite composition

Of the following which is NOT a physical property? A. Melting point B. Density C. Boiling point D. Color E. Ability to react with oxygen

E. Ability to react with oxygen

Which one of the following is an example of a physical property? A. dynamite explodes B. gasoline burns C. a silver platter tarnishes D. meat rots if it is not refrigerated E. ice floats on top of liquid water

E. ice floats on top of liquid water

Select True or False: Fermenting of grapes is physical change.

False

Select True or False: The corrosion of a metal is a physical change.

False

To solve for Volume

Mass/ Density

To solve for Density

Mass/ Volume

Select True or False: Water boiling at 100oC is a physical property.

True