one carbon atom differs from another in the number of neutrons and in the number of electrons. carbon atoms differ from all uranium atoms in terms of the number of protons, neutrons and electrons and also in their chemical properties.

N represents the nitrogen element and stands for naturally occurring mixture of all isotopes. the symbol 14N represents isotope with mass number 14 while 15N represents an isotope with mass number 15

1. 94 protons
2. Neptunium Np (93 protons), Plutonium Pu (94 protons)
3. 86 protons

a: control rod assembly
b: cooling water out of the core
c: control rod
d: cooling water into the core
e: fuel rods

Desalination is not widely used because the process requires a lot of energy, making it expensive to produce drinking water.

The water-soluble vitamins would be expected to be polar because “like dissolves like”. As water is a polar molecule, a water-soluble molecule would be expected to be polar, too. Fat-soluble vitamins would not be polar.

a. Air drying the laundry will avoid us using dryers. This will reduce the electricity consumption, which will allow us to burn less coal as a result and reduce the SO2 emission.

b. Walk, bike or take public transport will reduce the number of cars on the road. This will reduce the use of petrol, which will reduce the emission of nitrate oxides.

c. Reduce the number of times of using the appliances will reduce the use of electricity. This will allow us to burn less coal, which will reduce the amount of SO2 emission.

d. More heat can be stored and conserved in the water heater. This will avoid using electricity again to reheat the water.

e. Buying food that are locally grown can save the environment by reducing the pollution caused in the process of transportation; plane, ship, lorry will consume diesel and emit CO2 and NO2.

a. Coal fire plants release colossal amounts of water vapor along with the combustion process. The hydrogen and the carbon in the coal make at least twice the amount of water as the coal burnt when vapor is cooled it becomes visible as fog and becomes “smoky”.

b. The natural pH of rain is 5.4 (from lecture slides). Since the rain in the park is 10 times more acidic than natural, its pH is 1 less. Hence, it has a pH of 4.4.

a: Exothermic. Heat is released during combustion
b: Endothermic. Heat from the body allows water from the skin to change from liquid to gas and evaporate
c. Endothermic. Heat is absorbed from surrounding to melt the ice from solid to liquid

The bond energy of the products are larger than those of the reactants . This will lead to a large negative net energy indicating on an exothermic reaction. Hence, products should have a higher bond strength than reactants.

Heat is energy that that is transferred from one body to another as a result of a difference in temperature. In this case, when you touch a cup of coffee, what you feel is heat. On the other hand, temperature is a measure of hotness/ coldness expressed in terms of any scales like Celsius / Fahrenheit. Hence, if you use a thermometer to measure the hotness of the coffee, that is temperature.

a. 98% isooctane and 2% n-heptane
It has a higher octane rating than other blends sold at gasoline stations and hence is more resistant to knocking than these blends.

b. The octane rating provides no information about whether or not the fuel contains oxygenates. other labels around the pump should reveal this information.