Question

#1: For which of the following activities might you want to hire a chemist?

A. testing a sample of water from a well

B. finding a comet

C. examining the structure of plant cells

D. building a garage
**My answer: A

#2: Which of the following procedures involves a physical change in one of the substances?

A. creating salt by reacting sodium metal and chlorine gas

B. allowing a nail to rust

C. building a model rocket propelled by mixing baking soda and vinegar

D. grinding chalk into a fine powder
***My answer: D

Answer 1

do they look right?? :)

Answer 2

both correct!

Answer 3

#3: You have three molecules of glucose (3C6H12O6). How many oxygen atoms do you have?

A. 1

B. 3

C. 6

D. 18
***idk :(

Answer 4

i know carbon is 18 right??

Answer 5

so would oxygen be 6??

Answer 6

or would it be 18 ??? idk :(

Answer 7

\[3C _{6}H _{12}O _{6}\]

so the number in the front basically says how many times you multiply the entire number of atoms by. the little one in front of the specific atom says how many of those you have in 1 molecule

Answer 8

so 3 x 6

Answer 9

so 3 x 6= 18?? so my answer is D. 18???

Answer 10

yep!

Answer 11

aweosme!! thanks :)

Answer 12

no probs! :)