You have to think about the fact that hot air is constantly being blown up elevating the balloon once that air is taken away it's up to the steering and the wind after that. I know that probably doesn't help did you want to know the science part?
Answer:
Nickel has an atomic number of 28,so it has 28 electrons
Nickel has 10 valence electrons
Answer:
14 J of heat
Explanation:
Recall that the enthalpy of reaction is defined as the enthalpy change that occurs in a system when matter is transformed by a given chemical reaction, if all reactants and products are in their standard states. Here we have the heat of formation of six moles of the substance and we are expected to use it to obtain the the heat of formation of one mole of the compound and we can do that by simple proportion as shown below;
If 6 moles of the compound produces 84J of heat
1 mole of the substance will produce 1×84/6 = 14 J of heat
The smallest units is a formula unit