<span>If all chemical reactions that release free energy tend to occur spontaneously,why haven't all such reactions already occurred? One reason is that most reactions require an input of energy to get started.Before it is possible to form new chemical bonds,even bonds that contain less energy,it is first necessary to break the existing bonds,and that takes energy.The extra energy required to destabilize existing chemical bonds and initiate a chemical reaction is called activation energy.</span>
Explanation:
What is the purpose of the scientific method?
<em><u>ans/</u></em>
the goal of any scientific method is to solve a problem or to better understand an observed event.
b.
i. What does the law of conservation of energy say?
<em><u>ans/</u></em>
The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
ii. List two different kinds of energy.
<em><u>ans/</u></em>
Potential energy.
Kinetic energy.
iii. What does the law say about changes energy can undergo?
<em><u>ans/</u></em>
The implication of the Law of Conservation of Energy is that for any energy conversion, if a certain type, or form, of energy gets reduced by a certain amount, then another type of energy must increase by the same amount.
The answer is <span>a. kinetochore.
A kinetochore is a protein structure that holds the </span><span>sister chromatids to the spindle fibers. It is the place on chromatids where the spindle fibers bind during the cell division. As the result, sister chromatids are pulled apart to the opposite ends of the cell.</span>
Answer: 12g
Explanation:
The amount of energy (Q) required to raise the temperature of a substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Given that:
Q = 216 joules
Mass of aluminium = ? (let unknown value be Z)
C = 0.90 JºC-1g-1
Φ = (Final temperature - Initial temperature)
= 35°C - 15°C = 20°C
Then, Q = MCΦ
216 J = Z x 0.90 JºC-1g-1 x 20°C
216 J = Z x 18 J°g-1
Z = (216J/18 J°g-1)
Z = 12g
Thus, the mass of the aluminium is 12grams
