Which of the following 3 statements are true? A Valence electrons are only found in the nucleus of an atom
B Electrons are negative and Protons are positive
C Protons and electrons are both negative
D
Valence electrons are only found in the outer most shell of an atom
E
Protons and electrons are found in the nucleus
F
Protons and neutrons are found in the nucleus and electrons are found in the cloud
G
Protons and neutrons are both positive

B,D,F

Explanation:

Protons are positive, electrons are negative and neutrons have no charge.

The protons and neutrons are found in the nucleus and the electrons are found in the electron shells/cloud

Valence shells mean the outermost shell. therefore valence electrons would be on the valence shell ( The outermost shell).

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.