A system that releases heat to the surroundings, an exothermic reaction, has a negative ΔH by convention, because the enthalpy of the products is lower than the enthalpy of the reactants of the system. The enthalpies of these reactions are less than zero, and are therefore exothermic reactions
1 mole = 6.022*10^23 atoms
4.2 moles sulfur = 4.2* 6.022 * 10^23 sulfur atoms = 2.421*10^24 sulfur atoms
1 mole sulfur = <span>32.065 g sulfur
4.2 moles sulfur = 4.2 * </span>32.065 g sulfur = 128.901 g sulfur
Gasses the most abundant natural occurring gas is nitrogen which makes up 78% of the air.
<u>Answer:</u>
5
<u>Explanation:</u>
We know that,
number of count of cardinals = 75; and
measured area = 15 square kilometers.
To find the population density of the cardinals in an area of 15 square kilometers, we need to divide the number of cardinals by the given unit area:
Population density of cardinals = 75 / 15 = 5
Therefore, the population density of cardinals in an area measuring 15 square kilometers is 5.