Question

#1: You heat two substances, A and B. Both substances change color. When cooled, both substances return to their original colors. What most likely happened?

A. A physical change occurred in both substances.

B. A chemical change occurred in both substances.

C. A physical change occurred in substance A, and a chemical change occurred in substance B.

D. A chemical change occurred in substance A, and a physical change occurred in substance B.

****my answer: A. physical change in both

Answer 1

#2: How many grams are in a 5 pound sample? Express your answer in scientific notation with two significant figures. (1 pound = 453.592 grams)

A. 2.26 x 10^2g

B. 2.268 x 10^3g

C. 1.1 x 10^4g

D. 2.3 x 10^3g

***my answer: D.
is that right??

Answer 2

#3: Conditions for an experimental chemistry reaction require a temperature of 298 K. The temperature in the lab is 55°F. Which of the following must you do to meet the requirements? (°F= 9/5 (K - 273) + 32)
A. increase the room temperature by 22°F
B. decrease the room temperature by 12°C
C. decrease the room temperature by 33°F
D. increase the room temperature by 18 K
***My answer: A. increase by 22 degrees Fahrenheit

Answer 3

yep! they just heated up

Answer 4

do they look right to you?? :)

Answer 5

wait so ALL of them are correct?? :(

Answer 6

*** :) lol

Answer 7

or just #1??

Answer 8

sorry i was checking #3 they're all correct

Answer 9

oh okay, its all good :) so yayy :) thank youuuu