Answer:
Option A. Dense water floats.
Explanation:
Ocean circulation act as conveyor belt which transport warm water from the tropics towards poles from where cold water sinks to the deep ocean. It is also known as the thermohaline circulation because it is driven by salinity and temperature.
However, change in climate causing these ocean's thermohaline current to slow down because influx of cold and melting fresh water from the polar region is disrupting these circulation as influx of fresh water making the water less saline and less dense and hence it become harder to sink to deep ocean.
Tough question, I would suggest using Google maybe, or just plain out asking your science teacher.
Answer:
20.(45)L or about 20.4545L
Explanation:
PV = nRT
Where:
P - pressure
V - volume
n - number of particle moles
R - a constant
T - temperature in K
We can assume the P and n (and definitely R) stay the same, so we infer that

Answer:
The time taken for the cross to become invisible decreases.
Explanation:
We know that one of the factors affecting the rate of reaction is the concentration of reactants. From the collision theory, we know that the higher the concentration of reactants, the greater the possibility of effective collision between reactants leading ultimately to an increase in the rate of reaction. Increase in the rate of reaction implies that the reaction takes a shorter time to reach completion.
In the case of the reaction shown in the question, the point when the reaction is completed is observed by the time take for the cross mark to become invisible. If we look at the given data closely, we will notice that the volume of acid was held constant, the volume of thiosulphate was increased gradually while the volume of water was decreased accordingly. This implies that the concentration of the reactants was increased. Decreasing the volume of water increases reactant concentration.
As explained above, increase in reactant concentration increases the rate of reaction. Hence, the rate of reaction of the acid and thiosulphate increases as reactant concentration increases and the cross mark becomes invisible faster. This implies that in the last column for time taken for the cross to become invisible, the values of time decreases steadily as concentration of reactants increases.
Answer:
c) the attraction of an atom for the electrons in a covalent bond.
Explanation:
Electronegativity, symbol χ, is a chemical property describing an atom's ability of to attract a shared pair of electrons to itself. It is influenced by the atomic number of the atom and the distance between the valence electrons and the charged nucleus. As the electronegativity number of atoms increases, the more the atom attracts electrons towards itself.