Answer:
Hello the answer for the volcanos is here below:
7. Pipe
8. Crater
9. Vent
10. lava flow
11. magma chamber
Hope this helps :)
Explanation:

Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products. These reactions lower the temperature of their surrounding area, thereby creating a cooling effect. Physical processes can be endothermic as well – Ice cubes absorb heat energy from their surroundings and melt to form liquid water (no chemical bonds are broken or formed).
When a chemical bond is broken, it is usually accompanied by a release of energy. Similarly, the formation of chemical bonds requires an input of energy. The energy supplied/released can be of various forms (such as heat, light, and electricity). Endothermic reactions generally involve the formation of chemical bonds through the absorption of heat from the surroundings. On the other hand, exothermic reactions involve the release of heat energy generated from bond-breakage.
Endothermic Reaction Examples
Ammonium nitrate (NH4NO3), an important component in instant cold packs, dissociates into the ammonium cation (NH4+) and the nitrate anion (NO3–) when dissolved in water
Answer:
Hb would be 78.4% saturated.
Explanation:
This problem can be solved by using simple unitary method.
At 100 mm Hg pressure of oxygen, Hb is saturated by 98%
So, at 1 mm Hg pressure of oxygen, Hb is saturated by
%
Hence, at 80 mm Hg pressure of oxygen, Hb is saturated by
% or 78.4%
Therefore, at 80 mm Hg pressure of oxygen in the lungs, Hb would be 78.4% saturated.
Answer:
1)Na2O
let the valency of Na is x
2(x)+(2)=0
2x+2=0
2x=-2
x=-1
2)ZnO
let the valency of Zn is x
x+2=0
x=-2
3)Al2O3
let the valency of Al is x
2(x)+3(2)=0
2x+6=0
2x=-6
x=-3
4)MgO
let the valency of Mg is x
x+2=0
x=-2