Chemistry Test 3

If you were to compare how quickly different brands of chocolate-coated ice cream bars melted, with one experimental group for each brand, what should the control group be and why?

• there should be no control group because a control group is not needed because two or more experimental groups are being compared.
• ice-cream bar with the ice cream removed; a control group should not have the independent variable
• ice-cream bars with chocolate coating removed; a control group should not have the independent variable
• homemade ice-crea bars; a control group should be as similar as possble to the experimental groups

Tags

NGSS.MS-PS2-2

In the engineering design process, a model of a design that is used for testing is called a ???????

• rototype
• qutototype
• prototype
• sototype

Tags

NGSS.MS-ETS1-4

How close a measurement is to its actual, exact value is its ??????

• accuracy
• precision

If 7,830,000,000 is converted to scientific notation, the power of 10 should be ????

• 10^-9

• 10⁹

• 10^-7

• 10⁷

A length in yards should be multiplied by ????????? to convert it to meters. (1 yd = 0.9144 m)

• 1 m/0.9144 yd.
• 1 yd./0.9144 m
• 0.9144 m/1 yd
• 0.9144 yd./1 m

How many significant digits are in 0.0560?

• 2
• 3
• 4
• 5

The state of matter that is difficult to compress and has particles that are close together but free to move is ?????????

• liquid
• plasma
• gas
• solid

The chemical symbol for copper is ????

• Co
• Cr
• Cu
• C

A mixture of pure substances that are incompletely mixed and form distinct phases is a ????????? mixture.

• heterogeneous
• homogeneous

In nitrogen dioxide and dinitrogen pentoxide, the masses of oxygen that combine with 15 g of nitrogen are in a ratio of approximately 4 to 5. This fact demonstrates the law of ??

• definite composition
• multiple proportions