Octet means presence of a total of 8 electrons in its valence shell while in case of duplet only 2 electrons are present in valence shell.
Answer:
Explanation:
13 ) symbol of enthalpy change = Δ H .
14 ) enthalpy change is nothing but heat absorbed or evolved .
During fusion enthalpy change
Δ H .= m Lf , m is mass and Ls is latent heat of fusion
During evaporation, enthalpy change
Δ H .= m Lv , m is mass and Lv is latent heat of evaporation
during temperature rise , enthalpy change
Δ H = m c Δ T
In case of gas , enthalpy change can be calculated by the following relation
Δ H = Δ E + W , Δ E is change in internal energy , W is work done by gas.
15 ) When enthalpy change is negative , that means heat is released to the environment .So reaction is called exothermic .
when heat is absorbed enthalpy change is positive . Reaction is endothermic.
It’s
1.A
2.C
3.B
hope it’s correct
D. Wind will always move from areas of high pressure to low pressure. It's the reason we have weather, or one of them. Temperature is another factor.
B. That is the definition of the greenhouse effect.
