Will give brainliest!

What percentage of a substance remains after 7 half-lives have passed?

2.5

1.25

0.78

0.39

A janitor comes across a spilled substance on the floor of a high school chemistry lab. He wants to make sure the liquid is neutral before he cleans it up. What would be safest to add to the puddle? A. Pour on a base B. Pour on a buffer C.

Which term is defined as "anything that has mass and occupies space"?

What type of weather does low air pressure bring

If a lithium atom loses one electron, what will its charge be? a. - 2 b. - 1 c. 1 d. 2

A cube has sides of 11.4 cm. What is its volume? A) 1,482 cm3 B) 130 cm3 C) 1,443 cm3 D) 34.2 cm3

Which average wind speed do areas need to effectively power wind farms? A:1 mph B:5 mph C:10 mph D:16 mph

What is the total number of moles represented by 20 grams of CACO3 A. 0.1 B. 0.2 C. 1 D. 2

Which describes the polarity in a water molecule? a). partial negative charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms b).

To what temperature in kelvin will a 2.3 L balloon have to be heated to expand to a volume of 400 L Assume the initial temperature of the balloon is 25 degrees celsius.

In which changes of state do atoms lose energy?