Answer:
Explanation:
(a) Balanced reaction of gallium with oxygen is as follows:

(b) 
Multiply the carbon dioxide by 6 to balance carbon as follows:

After that multiply H2O by 7 to balance hydrogen as follows:

Finally balance oxygen by multiplying O2 by 19/2. Therefore, balanced reaction is as follows:

(c) 
first balance calcium, by multiply
by 3 as follows:

After that balance phosphorous by multiplying
by 2 as follows:

Finally balance Na by multiplying NaCl by 6. Therefore, balance reaction is as follows:

Answer:What are the two half reactions that show how many electrons are gained or lost by each species in the reaction:
Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq)?
atoms cannot be created or destroyed in a chemical reaction