The oxidation number of H is -1.
Sum of the oxidation numbers in each element =
charge of the complex
CaH₂ has 1 Ca atom and 2H atoms. The charge of
the complex is zero. Let’s say Oxidation number of H is "a".
Then,
<span> (+2)
+ 2 x a = 0 </span>
<span> +2 + 2a = 0</span>
2a = -2
a = -1
Hence, the oxidation number of Hydrogen atom in CaH₂ is -1
1023 molecules or atoms depending on substance
I believe the correct answer would be that electronegativity generally increases moving from left to right across a period. The periodic table of elements is arranged so that trends of the properties of the elements can be shown. For electronegativity, it decreases from right to left which means for the opposite direction it increases.
The answer is a change in internal energy causes work to be done and heat to flow into the system.
<u>Explanation:</u>
- The first law of thermodynamics is a similar version of the law of conservation of energy where the energy can neither be created nor be destroyed, it can be transformed from one form to the other.
- It also defines that the work is done and heat flowing into the system is due to the change in internal energy. The sum of all energy including kinetic and potential energy except the displaced energy to the surrounding is known as internal energy.
- ΔU represents the change in internal energy of the system, Q represents the net heat transferred into the system, and W represents the net work done by the system. So +ve Q adds energy to the system and =ve W takes energy from the system. Thus ΔU=Q−W.
C, the amount of oxygen produced is the dependent variable since that is what is being measured and it is dependent on which substance is being tested
