1. There are uncertainties in cloning. Some traits go wrong resulting in defects in the cloned dog.
2. To improve a dog breed, cross-breeding should be the way. Cloning is to get an exact copy of the dog. Hence, no improvement in the dog breed is in the cloned dog. Therefore, cloning cannot improve the dog breed.

Pros :
1. Alleviate widespread hunger issues in the country because genetically modified corn is resistant to heat.
2. Save costs because less crops will die and hence increase output.

Cons :
1. Unaware of the effects of genetic engineering. Allergies may be present.
2. Ecosystem will be harmed, diversity will be affected.

Yes, we will accept it.

a

a

a

Acetone dissolve foaming agent in styrofoam where it evaporates. Foaming agents are removed too. Therefore PS is the denser substance. Styrofoam contains a lot of air. Dissolves the polymer –> Gas escapes –> molecules can rearrange into a more compact structure –> denser

a. Branched LDPE does not have a high resistance to being cut due to weak IMF. Therefore, it cannot be used for liners in surgical gloves. LDPE is flexible and not resistant to cut due to branched polymetric structure –> weak IMF

b. Linear HDPE is stronger than LDPE because there are higher surface of contact for intermolecular forces of attraction to occur. Thus HDPE is stronger.

It does not happen to papers as it does not have the structure to allow for dislocation motion of its atoms. Since dislocation motion does not happen, deformation does not happen. Dislocation motion = slipping of a group of bonded atoms along the dislocation plane. Polymer: % molecules –> IMF –> Weak forces of attraction –> broken and reformed quickly –> broken and reformed = stretchable
Paper: IMF stronger, cannot reform after being broken –> the attractive forces % the molecule becomes permanently broken and thus the paper is being torn and not stretchable.

a. Non toxic, non biodegradable, chemical resistent to rust, chemically stable, bio-compatible.
b. polymethylmethacrylate (Hard lenses)
hydro gels hydroxymethylmethacrylate (Soft Lenses)
contact lens have to be hydrophilic, allow oxygen transport to cornea. It must be soft so that it can fit the shape of the eye. It should also be flexible.
c. Hard lenses are difficult to adapt to, gas permeable, free of toxic chemicals and are more suited for people with high astig. Soft lenses are easier to wear because they are more flexible than hard lenses.

1. Neutron number: C12 has 6 neutrons and C14 has 8 neutrons
2. Electron number: C- has 7 electrons, C+ has 5 electrons and C has 6 electrons

14N has 7p, 7e and 7n
15N has 7p, 7e and 8n
Both are isotopes and N represents for Nitrogen.

p: protons
e: electrons
n: neutrons

a) 94 protons
b) Neptunium (93 protons), Plutonium (94 protons)
c) 86 protons

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

Desalination is not a fail safe process and carries many environmental repercussions. Desalination requires pre-treatment and cleaning chemicals are added to the water for efficiency and success. Chemicals include: chlorine hydrochloric acid, hydrogen peroxide, which can only be used for a limited time, once it loses the ability to clean the water, the chemicals are dumped, which causes environmental concerns. By products of chemicals used in desalination can get through into ‘pure water’ and endanger people who drink it. Futhurmore, it can be acidic to both pipes and digestive systems. It is more costly than reverse osmosis and less effective than reverse osmosis.

Either of them are polar. Vitamins that are water soluble have hydrogen bonds between water molecules and the H-O, H-N sites of the vitamins. Hence, the molecule is most likely polar due to the H-O bonds and H-N bonds. Vitamins that are fat soluble are non-polar compounds because the major group in fatty acid fats is the alkyl chain which can exhibit van de waals forces with other alkyl, non-polar groups, hence they are fat soluble and is non-polar vitamins. Like dissolves like. Water: polar therefore vitamins that are water soluble are polar. Oil: non-polar, therefore vitamins that are fat soluble are non-polar.

A,C,D: decrease electicity usage –> decrease amount of fossil fuels burtn –> decrease emissions of Nox and SOx –> decrease acid rain
B,E: decrease pollutant emission from transportation –> decreaseNOx and SOx –> decrease acid rain

(a) Coal fired plants emit a lot of harmful sulfate, carbon and nitrate particles. Soot, a type of carbon particle is also released. These particles tend to absorb light rather than scatter them, resulting in poor visibility as such particles build up in our environment. Small droplets of SO3
(b) PH=4 since every decrease in PH by 1 is equals to the increase of hydronium ions by 10 times. Normal rain water PH = 5.6

Endothermic: (b), (c) – Surrounding feels cooler as energy is absorbed. Hydrogen bonds are broken. Van der Waal’s between H and N/O/F that exist % molecules that have hydrogen directly attached to N/O/F.
Exothermic: (a) Heat is produced and we can feel it. Energy released from bonding forming is more than energy released from bond breaking.

Bond strength of products would be strong than the bond strength of reactant such that the enthalpy change of combustion would be higher. Energy level of product is lower and energy level of reactant is higher. Product should be gases instead of liquid and solid.

Temperature is a measurement, not a form of energy and thus cannot be transferred whereas heat is a form of energy that can be transferred from a hotter substance to a colder substance. Heat is produced when water boils and we would need a thermometer to measure the temperature of the water.
Heat – Internal energy of a substance
Temperature – Measure of the amount of energy that a substance contain.

(a) It is 98% isooctane and 2% hexane in terms of knocking charcteristics, where isooctane is assigned a value of 100.
knocking: Preignition -> ignition during compression
(b) We do not know. If we want to know if additives/oxygenates added, we need to look deeper/ find developer.

Endothermic: (b), (c) – Surrounding feels cooler as energy is absorbed.
Exothermic: (a) – Heat is produced and we can feel it.

Bond strength of products would be stronger than the bond strength of reactants such that the enthalpy change of combustion would be higher.

Temperature is a measurement, not a form of energy and thus cannot be transferred whereas heat is a form of energy that can be transferred. Heat is produced when water boils and we would need a thermometer to measure the temperature of the water.

(a) It is 98% isooctane and 2% hexane in terms of knocking characteristics, where isooctane is assigned a value of 100.
(b) The fuel does not contain oxygenates. Methanol, ethanol and MTBE contain oxygenates and have a value above 100. Hence, if a gasoline has an octane rating of 98, it should not contain oxygenates.

Any particle that has a diameter of 10 micrometre or less. It is a mixture of solid particles and liquid droplets. Three examples of particulate matter are soot, dust and ash. PM 10 can easily get into lungs while PM 2.5 is implicated in heart diseases.

(a) 9000ppm
(b) smoker –> 0.002 – 0.005%
non smoker –> 0 – 0.0002%
(c) 5%
(d) 0.001%

3. Consider this representation of the reaction between nitrogen and hydrogen to form ammonia (NH3).

a. Are the masses of reactants and products the same?
b. In a tropical rain forest, the water vapour concentration may reach 50,000 ppm. Express this as a percent.
c. Are the total number of atoms in the reactants and the total number of atoms in the products the same?

(a) Yes
(b) No
(c) Yes

It is better to use 0.01 ppm because not many people know about the unit ppm. Thus people will not be as astonished by the increased in ozone reading. 0.01% also looks smaller than 8.

Pedestrians inhale less pollution than passengers.

NIL