Answer:
.A catalyst provides an alternate mechanism for the reaction
Explanation:
The catalyst provides a mechanism of reaction having the lowest activation energy. It lowers the energy barrier between reactants and products hence it increases the rate of reaction by several orders of magnitude
Answers:
(a) The explanatory variable is the change in the temperature
.
The response variable is the coral survivance.
(b) The explanatory variable is quantitative.
The response variable is categorical.
Explanation:
A quantitative variable is those that can take a range of values. In this case, the temperature may vary across a range of values associated with the survival of coral reefs.
A categorical (also known as qualitative) variable is characterized to present finite states. In this case, the coral reefs can survive or not depending on their responses to changes in the temperature.
The answer is C, because wind turbines are used to produce electricity, and it's also the most safest way--but they are expensive.
Oceanic crust is more dense because it contains basalt which is more dense than granite which composes the continental crust.
Answer: Option D is correct.
Explanation: Equation given by de Broglie is:

where,
= wavelength of the particle
h = Planck's constant
m = mass of the particle
v = velocity of the particle
In option A, football will have some mass and is moving with a velocity of 25 m/s, hence it will have some wavelength.
In Option B, unladen swallow also have some mass and is moving with a velocity of 38 km/hr, hence it will also have some wavelength.
In Option C, a person has some mass and is running with a velocity of 7 m/hr, hence it will also have some wavelength.
As, the momentum of these particles are large, therefore the wavelength will be of small magnitude and hence, is not observable.
From the above, it is clearly visible that all the options are having some wavelength, so option D is correct.