Answer:
The answer to your question is 3.69 x 10²¹ atoms of gold
Explanation:
Data
density = 19.32 g/cm³
dimensions = 2.5 cm x 2.5 cm x 0.1 mm
number of atoms of gold = x
Process
1.- Find the volume of the foil
Volume = length x height x width
Volume = 2.5 x 2.5 x 0.01
Volume = 0.0625 cm³
2.- Calculate the mass of the foil
Density = mass/volume
mass = density x volume
mass = 19.32 x 0.0625
mass = 1.208 g
3.- Calculate the number of atoms
Atomic number of Gold = 197 g
197 g -------------------- 6.023 x 10²³ atoms
1.208 g --------------- x
x = (1.208 x 6.023 x 10²³)/197
x = 3.69 x 10²¹ atoms of gold
<h2>1.CHEMICAL ENERGY</h2>
THEY HAVE CHEMICAL ENERGY
<h2>2.BECAUSE IT PROTECTS PLANT</h2><h3>EXPLENATION</h3>
- Coal-fired plants produce electricity by burning coal in a boiler to produce steam. The steam produced, under tremendous pressure, flows into a turbine, which spins a generator to create electricity. The steam is then cooled, condensed back into water and returned to the boiler to start the process over.

-130KJ is the standard heat of formation of CuO.
Explanation:
The standard heat of formation or enthalpy change can be calculated by using the formula:
standard heat of formation of reaction = standard enthalpy of formation of product - sum of enthalpy of product formation
Data given:
Cu2O(s) ---> CuO(s) + Cu(s) ∆H° = 11.3 kJ
2 Cu2O(s) + O2(g) ---> 4 CuO(s) ∆H° = -287.9 kJ
CuO + Cu ⇒ Cu2O (-11.3 KJ) ( Formation of Cu2O)
When 1 mole Cu20 undergoes combustion 1/2 moles of oxygen is consumed.
Cu20 + 1/2 02 ⇒ 2CuO (I/2 of 238.7 KJ) or 119.35 KJ
So standard heat of formation of formation of Cu0 as:
Cu + 1/2 02 ⇒ CuO
putting the values in the equation
ΔHf = ΔH1 + ΔH2 (ΔH1 + ΔH2 enthalapy of reactants)
heat of formation = -11.3 + (-119.35)
= - 130.65kJ
-130.65 KJ is the heat of formation of CuO in the given reaction.
Answer:
ans is (2) 2,4- hexadiene