Cloning results in replicating the same dog breed, whereas not improving the dog breed. To improve, we require natural selection, gradually evolving the breed.

Pros:
1. Higher yield since it is pest-resistant
2. Higher in nutrition value
Cons:
1. Unknown health risks, may trigger allergy
2. Lower level of biodiversity –> contamination
Decision: We will accept the GM corn in the short run, in order to reduce the risk of famine; look for a long run solution at the same time.

a) Cn(H20)n
c) Different isomers have different chemical properties, hence different sweetness among the isomers.

It is impossible to go on an all organic and chemical-free diet because water is an example of a chemical, and it is not possible that food is water-free. It is a marketing gimmick to convince people to buy their products. The chemicals present in the food depend on the type of the chemical and the source of it. Therefore, no food produced can be all organic and chemical-free.

Acetone will dissolve the Styrofoam (polymer), allowing gas of foaming agents to escape. The polymer then collapses on itself, and become more dense due to the absence of the gas.

a. LDPE is much weaker than HDPE, hence it can tear more easily. It will not be ideal for surgical gloves.
b. The molecules of HDPE must line up in a way that produces the require of strength. Using a thin layer of HDPE allows sufficient flexibility.

No. In the piece of plastic, the molecules are aligned in the direction of the pull, along with the weak but extensive dispersion forces allowing the molecules to slip pass one another, hence the plastic is able to stretch without breaking. As for the paper, the molecules are more rigid and will not align in the direction of the pull. therefore, it breaks apart when force is applied.

a. Chemical resistant, high toughness, stable and does not react with body fluids, non-toxic
b. Contact lenses are made of polyacrylamide/silicon. Properties desired are:
1. unreactive (especially on eye surface)
2. flexible
3. tough
4. easy to mould
c. “Hard” contact lenses are made of PMMA, which is rigid, and non gas permeable. This type of contact lenses will be more uncomfortable for the users.”Soft” contact lenses are made out of a polymer material which allows O2 to pass through, hence more comfortable for the users.

a) Isotopes, difference in no.of neutrons
Carbon ions, carbocation (C+), carbanion (C-) and carbon atom.

b) 1. atomic number
2. no. of neutrons
3. chemical properties

The chemical symbol N assumes the naturally occurring isotope 14N. Representation 14N and 15N indicates the no. of neutrons, and hence difference between the 2 isotopes.

a. 94 protons
b. 93 protons –> neptunium ; 94 protons –> plutonium
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

1. high energy consumption, thus energy cost is too high for it to be a long term and sustainable solution.
2. costs a lot of money, thus is not easily affordable.
3. produces a large amount of carbon emission, thus damaging the atmosphere and ozone layer.

water soluble vitamins: polar compounds, since water (H20) is polar, polar can dissolve in polar).
fat soluble vitamins: non-polar compound

a. doesn’t lead to any emission of fuels
b. less vehicles = less emission of harmful chemicals
c. less electricity = less burning of fuels = less emission of harmful gases
d. increase efficiency of power used = less usage of fuels
e. no transportation of goods required = less emission of NO2

a. coal plants release huge amount of water vapour, which when cooled becomes visible as fog. When the temperature is cooler at night, it leads to fog formation and cooler day temperature makes it lasts longer.
b. Average pH of rain is neutral = ph7, thus if acid level is 10 times stronger, it is equal to 1pH. The estimated pH of rainfall in the park should be pH6.

a. Exothermic. When charcoal is burnt, it feels warm and hence we can assume that heat is released.
b. Endothermic. When water evaporates from our skin, it feels cool because water absorbs heat from our skin to evaporate.
c.Endothermic. When ice melts, it changes to liquid form (water). In order for it to melt, it needs to take in heat from surroundings. Hence, the process is endothermic.

For a good explosion, the chemical explosion needs to release a lot of energy and hence, it is a highly exothermic reaction. The net bond strength is a very large negative number. Hence bond strengths of products must be much lower than bond strengths of reactants. Gases are able to produce high energy release due to fast variation in volume change.

Temperature: The number and type of energy.
Heat: Amount of energy measured in units.
E.g. Comparing a small cup of water with a big cup of water, both have the same temperature. However, the big cup of water has more energy due to a larger volume.

a. 98% isooctane and 2% n-heptane
b. Insufficient information is provided to deduce if the fuel contains oxygenates. Octane rating only gives info on quality of fuel.