Math
Fez is 3.25 years old, work out her age in months
39
What are the characteristics of all organisms?
A. Egestion and Excretion
B. Egestion and Nutrition
C. Excretion and Nutrition
D. Excretion and Photosynthesis
C. Excretion and Nutrition
Evaporation occurs from the surface of a pool of water. Which statement describes this change of state?
A. Electrons move from the liquid and become a gas.
B. Molecules that move from the liquid have the same energy as the molecules that stay in the liquid.
C. The more-energetic molecules escape the liquid.
D. The more-energetic molecules remain in the liquid.
C. The more-energetic molecules escape the liquid.
What is thin-layer chromatography best used for separating?
A. molecules of varying polarity
B. molecules of similar polarity
C. metals in an alloy
D. water of crystallization from hydrated salts
A. Molecules of varying polarity
State two naturally occurring greenhouse gases other than carbon dioxide
Methane
Nitrous oxide
Water vapour
Tropospheric/ground level ozone
Professor Vinculum investigated the migration season of the Bulbul bird from their natural wetlands to a warmer climate. He found that during the migration season their population, P could be modelled by P = 1350 + 400(1.25)^-t, t ≥ 0 , where t is the number of days since the start of the migration season. Find the population of the Bulbul birds at the start of the migration season
1750
Domestic dogs (Canis familiaris) have evolved from grey wolves (Canis lupus). Evidence suggests that the domestication of dogs first occurred around 30000 years ago. Which best describes the evolution giving rise to the domestic dog?
A. The wolf produced offspring in large numbers which underwent natural selection.
B. Variations in the wolf population that resembled modern dogs favoured wolf survival.
C. Wolves showing favourable traits were selected for breeding.
D. Dogs were better suited to changes in the natural environment than wolves.
C. Wolves showing favourable traits were selected for breeding
An alpha particle (He) of initial energy 5.5MeV moves towards the centre of a nucleus of gold‑197. What is the distance of closest approach of the alpha particle?
A. 1.0 × 10^-13m
B. 4.1 × 10^-14m
C. 2.1 × 10^-14m
D. 6.6 × 10^-33m
B. 4.1 × 10^-14m
What do all greenhouse gases have in common?
A. They are emitted by the burning of fossil fuels.
B. They absorb ultraviolet radiation.
C. They are symmetrical molecules with no polar bonds.
D. They absorb infrared radiation.
D. They absorb infrared radiaion
Explain one reason why a country could experience a demographic dividend
eg. an increase in the proportion of the working age population, as a result of falling fertility/birth rates
Let A and B be events such that P(A) = 0.5, P(B) = 0.4 and P(A ∪ B) = 0.6. Find P(A|B)
P(A|B) = 0.75
What allows the movement of water under tension in the xylem?
A. Adhesion of water molecules to dissolved mineral salts
B. Cohesion of water molecules due to hydrogen bonding
C. Adhesion between water molecules due to uneven sharing of charges
D. Cohesion between water molecules and other polar substances
B. Cohesion of water molecules due to hydrogen bonding
The ruler has cross-sectional area A = a × b, where a = (28 ± 1)mm and b = (3.00 ± 0.05)mm. Suggest an appropriate measuring instrument for determining b
The following data are collected during a titration.
Final burette reading = 16.10 ± 0.05cm^3
Initial burette reading = 1.10 ± 0.05cm^3
Calculate the percentage uncertainty of the titre.
0.7% or 0.667%
Explain two possible negative consequences for the cities projected to experience very rapid growth.
.