It's absolutely TRUE...........
Because of pollution from factories and other activities that release harmful gases into the air
Remember: energy is conserved in a chemical reaction (visualize the reaction and question whether heat lies on reactant side (left) or product side (right))
-exothermic- heat is released (heat is on the product side)
>forming an ionic lattice (SALT)- mixture of Na and Cl results in a more stable ionic lattice, causing this reaction to be exothermic
>burning wood
-endothermic- heat is absorbed (heat is on the reactant side)
> cooking an egg
To obey the Law of Conservation of Mass, the sum of all individual elements of a compound is equal to the mass of the compound. So, if HCN has a mass of 7.83 grams, then
7.83 g = mass of H + mass of C + mass of N
We know the masses of H and N to be 0.290 g and 4.06 g, respectively. Hence, we can find for the mass of C:
7.83 = 0.29 + mass of C + 4.06
mass of C = 3.48 g
As an extension to the Law of Conservation of Mass, there is also a Law of Definite Proportions. According to Dalton's atomic theory, a compound is formed from a fixed ratio of its individual elements. From our previous calculations, we know that the mass ratio of H to C to N is 0.29 g: 3.48 g:4.06 grams. The ratio could also be expressed in percentages. Let's find the mass percentage of Carbon in HCN to be used later:
mass % of Carbon = (3.48 g/7.83 g)*100
mass % of Carbon = 44.44%
So, if you collect a different mass of HCN, say 3.37 g, the corresponding mass of Carbon is equal to:
Mass of Carbon = (3.37)(44.44%)
Mass of Carbon = 1.498 g
The appropriate answer is b. greenhouse gases. Greenhouse gases such as carbon dioxide and methane have the ability to trap infrared radiation or heat in the atmosphere. Without these gases the Earth would be thirty degrees cooler than it is today. Pollution today has caused more of these gases to enter the atmosphere and this is the main cause of contemporary global warming.
Ozone in the stratosphere actually blocks another form of radiation called ultraviolet radiation. Geothermal energy is derived from hot rocks inside the earth.
