Clonging cannot be used to make improvement of dogs because the technique simply produces genetic replicas of existing dogs. Other disadvantages of cloning are mutations (resulting in unhealthy dogs), early death or premature aging when somatic cells undergo telomeric shortening during cloning, and reduction in genetic diversity.

Pros:
i)Help to alleviate hunger and malnutrition
ii)Multiple resistance (e.g. diseases / herbicide)
Easier growth and incerase yield

Cons:
i)Potential negative impact on the environment
ii)Potential to trigger allergic reaction

a) C6H12O6 = C6(H2O)6

b) D-Fructose and L-Fructose

c)No. The difference in structures will have different binding affinity to sweetness (taste) receptors, which elicits different neural response.

In reality, everything we eat, whether healthy or not, are composed of chemicals.
Even if the food is grown in organic/pesticides-free condition, there are chemicals brought about by rain may still contaminate these food. (e.g. pesticides flushed down from non-organic farms to organic farms by rain)
Packaging such as plastics containers can cause chemicals to be transferred to the food.

Styrofoam consist of mostly air and when dissolves in acetone, the polymer chains are able to slide around each other which in turn results in the release of air bubbles that are trap in the foam. As the acetone evaporated leaving the solid behind, this solid no longer contains air bubbles thus making it much denser.

a) LDPE is very fragile compared to HDPE. This is because LDPE consist of mostly amorphous structure that are arrange disorderly and hence making LDPE more softer and low resistance to being cut. The stronger, stiffer, more heat resistant and more flexible at lower temperature HDPE makes it more suitable compared to LDPE.

b)HDPE region of crystallinity is high and as they are arrange in orderly manner, they are more denser and stronger. Thus, successful in this application.

No, it does not happen. Plastic had weak but extensive dispersion forces which allow the molecules to slip pass one another hence allowing the plastic to stretch. Paper on the other hand is produce from cellulose. The multiple hydroxyl group from 1 chain form hydrogen bond with oxygen atom on a neighboring chain. It holds the chains firmly together side by side resulting in stiffness.

a) i.Stable and durable
ii.Upon disposal should be easily broken down
iii.Non-toxic
iv.Strong carbon backbone

b) For hard contact lenses: Polymethyl methacrylate (PMMA)
For soft contact lenses: Polyhydroxyethyl methacrylate (PHEMA)
The properties include transparent, flexibility, tough and hydrophilic.

c)For hard, it is rigid and not very comfortable. Also, it does not allow oxygen to pass directly to cornea. For soft, it is hydrophilic, soft and flexible.

Radioactivity (14C= radioactive, 12C= not radioactive)
Neutron number (isotopes)

Difference between carbon atoms and Uranium atoms
Half-life- carbon have shorter half-life compared to Uranium
Uses- carbon are commonly found in life form while Uranium is found in nuclear fission
Atomic Number- Carbon 6, Uranium 92

1) atomic mass is 14 for 14N and 15 for 15N
2)15N have one more neutron compared to 14N (Isotopes)
3) For both cases, the number of electrons and protons are the same. Since the no of electron mean same number of valence electron, they will have the similar chemical reaction

a) 94 protons
b) 93 =Neptunium
94 = Plutonim
c) 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 it not widely used due to its energy consumption. It burns up a lot of energy than sourcing equivalent amount of fresh water from fresh water bottles. Also, the process is very expensive and the residue produced is saline brine which needs to disperse without causing environmental problem. It has an adverse effects on coastal/marine life.

For water-soluble vitamins, we expect it to be polar compounds as “like dissolve like”. Since water itself is polar,these vitamins that are water-soluble too are polar.
For fat-soluble vitamin, they are not polar thus those vitamins that are fat-soluble will not be polar compounds.

a) Compared to using of clothes dryer, hanging laundry helps to reduce the use of electrical energy. Therefore, less is needed for burning of fossil fuel for energy production that result in decrease of sulfur dioxide being produce. Overall, reduce acid rain.
b) There will be reduce amount of NOx emission from power plants, vehicles, fossil fuel combustion thus reduce acid rain.
c) Wastage of electricity should accumulate into larger load. As using electricity requires burning of fossil fuels, avoiding using dishwashers and washing machines for small loads will reduce the amount of sulfur dioxide being produce thus reduce acid rain.
d) This is to prevent heat loss so less energy is needed so as less needed for burning fossil fuel and sulfur dioxide produce is reduce which in turn reduce acid rain.
e) There will be reduce in the need for transportation which will reduce in the amount of NOx emission thus reduce acid rain.

a) The burning of coal leads to production of sulfur dioxide. Once in the air, sulfur dioxide can react with oxygen molecules to form sulfur trioxide.
These Sox react with water to form acids. e.g SO2 (g) + H2O (l) -> H2SO3 (aq)
Such molecules of acid can form tiny droplets. These droplets form aerosols that do not absorb sunlight and instead they reflect it hence reduce visibility.

b)Usual pH of rain is 5 to 6. Therefore 10 times increase in acidity result in range of about 4 to 5.

1a) Exothermic: Charcoal briquette releases heat when it burns

1b) Endothermic: Water absorbs heat needed for evaporation by breaking bonds (H-bonding)

1c) Endothermic: (solid) –> (liquid) Ice absorbs heat so as to allow it to melt. When ice absorbs heat as energy, it gains kinetic energy until it reaches its melting point where it will exist as a liquid.

An example of a good explosion: methane combustion.

CH4 + 2 O2 –> CO2 + 2 H2O

For the reaction to be exothermic, the net change of energy must be negative i.e. the energy absorbed to break the bond must be less than the energy released during bond formation. The bond energies of the products should be larger than those of reactants.

In methane combustion, the bond energies involved are: C-H: 416KJ/mole, O=O: 498KJ/mole, H-O: 467KJ/mole and C=O: 803KJ/mole

Bond energies of reactants = 4 C-H + 2 O=O = 4 X 416 + 2 X 498 = +2660KJ/mole
Bond energies of product = 2 C=O + 4 O-H = 2 X 803 + 4 X 467 = -3474KJ/mole

Net change = 2660 – 3474 = -814KJ/mole

The bond energies of the product > bond energies of the reactant. Hence, net energy change is negative (as shown above). This indicates a large exothermic reaction.

Heat = energy transfer.
e.g. touching a hot coffee.

Saying that a hot coffee has “heat” = wrong.
A better statement = “This coffee can transfer energy as heat towards the lower energy (finger).”

Heat depends on the speed of particles; the number of particles and the type of particles in an object whereas temperature does not depend on size or type of object. Temperature is an intensive property.

e.g. when you boil eggs
You need X amount of water at 100-degree Celsius for you to cook one hard boiled egg. However, you will need either/both more than X amount of water or/and more time to cook two or more hard boiled eggs.

Octane rating = The measure of the ability of the gasoline to burn smoothly without knocking.

a) 98% isooctane + 2% heptane

b) It does not indicate if the fuel contains oxygenates