C. The total number of protons and neutrons in an atom.
In a neutral atom, the numbers of protons electrons are equal and also is equal to the atomic number. So mass # - atomic # = # of neutrons. Just some extra info there.
Answer:
Mg(s) + 2HCl (aq) ------> H2 (g) + MgCl2 (s)
Explanation:
Mg(s) + 2HCl (aq) ------> H2 (g) + MgCl2 (s)
before Mg -1, H -2,Cl -2
after Mg -1, H2, Cl - 2
Answer:
They lose two electrons.
Explanation:
When an atom loses are gain the electrons ions are formed.
There are two types of ions.
Anion
Cation
1 = Anion
It is formed when an atom gain the electrons. when atom gain electron negative charge is created on atom. For example.
X + e⁻ → X⁻
2= Cation
It is formed when an atom loses the electrons. when atom lose electron positive charge is created on atom. For example.
X → X⁺ + e⁻
There are two valance electrons in group two elements. They loses two electron to complete the octet and form cation with a charge of +2.
For example:
Mg → Mg⁺² + 2e⁻
S
+ O
→ SO
-71kcal
Explanation:
The reaction describe is a thermochemical equation. In the reaction above, since heat is liberated, this is an exothermic reaction.
- In an exothermic change heat is liberated to the surroundings.
- At the end of the reaction, the surrounding becomes hotter.
- The value of the heat change is assigned a negative sign.
1 mol of liquid sulfur (S (l)) = S
1 mol of gaseous oxygen (O2 (g)) = O
gaseous sulfur dioxide (SO2) = SO
releasing 71kcal = -71kcal
S
+ O
→ SO
-71kcal
learn more:
Energy changes in a reaction brainly.com/question/10567109
#learnwithBrainly
<span>A chemical change has occurred creating a precipitate.
Just had that question on a quiz. XP
Hope I helped :)</span>