The correct answers are
-formation of a precipitate
-bubble formation
-color change
-temperature change
-odor formation
The only one that isn’t correct is change in state of matter. A change in a state of matter does not mean it’s a chemical change. For example, water boiling so it turns into gas is not a chemical change, and is a physical one. Also, water can freeze and turn into ice, which is also still a physical change. If something changes state of matter, it does not necessarily mean it’s a chemical change.
3Zn + 8HNO3 ---> 3Zn(NO3)2 + 4H2O + 2NO IF IT IS COLD AND DILUT NITRIC ACID .
IF IT IS HOT AND CONCENTRATED THEN:
Zn+ 4HNO3 ---> Zn(NO3)2 +2H2O +2NO2
A. ca is the answer because its short for carbon
2 boxes of A
Because C = A + B
2 of A = 20 grams
at the other hand we have 2 of B = 10
So 20 + 10 = 30 grams