DNA sequence will be exactly the same so there will be no natural selection. In the case of a disease outbreak, all dogs will die because all of them have the same DNA, hence they are unable to adapt to changes and evolve. There will be a decrease in the gene pool.

Pros:
The drought resistant crops can grow in harsh conditions, providing food supply for the people. International relations will be improved and economy will be boosted by growing, selling or trading. There can be an increase in nutritional value.

Cons:
It might spread to the non-genetically modified crops. The eco-system may be disrupted.

We will accept the offer because we need to solve the problem of the famine first.

(a) C6(H2O)6
(c) No, isomers have different chemical properties.

Chemicals involve water and air and our bodies contains chemicals and in many ways, exposure to chemicals is inevitable. Large scale organic farms need to apply certain chemical solutions to their crops.

Styrofoam is made of polystyrene and this is readily soluble in acetone. Styrofoam contains a lot of air as it is made with foaming agents, thus when dissolved in acetone, the foam decreases in size as air exits the proton material.
As such, with the evaporation of acetone, the polystyerene hardens and becomes a solid, which is also much denser.

a. Branch LDPE is not very strong and thus has low resistance to being cut.
b. HDPE consists of long linear chains which have a larger extent of intermolecular forces of attraction thus they are stronger. However, due to the branching of LDPE, there is less intermolecular forces of attraction due to the decreased surface area, making it weaker.

No. Paper has lower ductility, so when pulling plastic there will be plastic deformation. This is the breaking of current bonds and forming of new bonds. Some of the initial intermolecular bonds are broken and as molecules slide into their new positions, new intermolecular bonds are formed between adjacent molecules, leading to deformation. However, paper has low ductility, so it does not stretch before breaking, and so it will just tear when pulled.

a. Durable, flexible, non-corrosive, non-toxic.
b. PMMA (polymethyl methacrylate) make up hard contact lenses, while hydroxyethyl methacrylate make up for soft, flexible hydrogel lenses. The desirable properties are non-toxic, hydrophilic, non-reactive, lightweight, transparent, frictionless, non-irritant, permeability to oxygen, neutrally charged, and flexible.
c. The material used for soft contact lenses allow for permeability of oxygen, making it more comfortable and easier to wear. This also makes allows soft contact lenses to be worn for prolonged periods of time, longer than hard contact lenses. Another difference is that soft contact lenses are more flexible and can be put on and taken off with greater ease.

Carbon atoms can have different number of neutrons, and have different atomic size and mass.
Carbon atoms are different from uranium atoms in atomic mass, number of protons, and half-life.

14N and 15N are isotopes. Mass number = Proton number + Neutron number.
As both have the same number of protons, they differ in the number of neutrons by 1.

a. 94
b. 93 protons – Neptunium (Np)
94 protons – Plutonium (Pu)
c. 86

A: Control rod assembly
B: Cooling water out of the core
C: Control rods
D: Cooling water into the core
E: Fuel rods

– Carries many environmental repercussions:

1. Desalination requires pre-treatment and cleaning chemicals, e.g. Cl, HCl acid and hydrogen peroxide. Once they lose the ability to clean water, the chemicals are disposed. Chemicals find their way back to ocean which will poison the aquatic plants and animals.

2. Energy-consuming. Other water treatments are more energy-efficient.

3. Slow process

4. Not fail-safe. It can be harmful to human health as by-products of the chemicals used may get into the water and endanger people who drink it.

Water is a polar molecule with the positive charges on one side and negative on the other. As the vitamins are water-soluble, they are polar compounds as like dissolves like. Hence polar vitamins dissolve in polar aqueous solution.

Fat is non-polar. Hence, vitamins that are fat soluble are non-polar compounds.

a) Saving energy. Release less harmful chemicals/by-products into environment

b) Minimise NOx production by vehicles. Reduce environmental pollution

c) Minimise SOx from the burning of coal to provide electricity for the machines

d) Less energy required to continuously heat up the water. Less amount of pollutants released into atmosphere.

e) Less pollutants as the amount of transport required is reduced.

a) When burning coal, tiny particles are released into the air that do not absorb sunlight but reflect it instead, reducing visibility.

b) Around pH 4-5

a) Exothermic, Heat energy is released from the charcoal to cook food thus when standing near charcoal people will feel hot.
b) Endothermic, Water absorbs heat from the skin as it evaporates and thus giving a cool feeling.
c) Endothermic, heat energy is absorbed to break the intermolecular forces as rigid ice becomes slippery liquid.

Since chemical explosions are highly exothermic, Reactants should have a low bond strength and products should have high bond strength. This would lead to negative H and thus an exothermic reaction.

Heat is the amount of energy in a system –> SI units Joules
Temperature is the measure of average molecular movements in a system –> SI unit Kelvin.

Everyday examples,
For temperature, just show your friend the thermometer.
For heat ask him/her to touch a stove.

98 Octane number tells us that it has a knocking characteristic of 98% isooctane and 2% heptane.

It can be assumed that octane number below 100 has no oxygenates as oxygenates are additives used to increase the overall rating of the gasoline.