1. The chemical reaction produced by Carlo's fire is exergonic because energy is "going out". As the reaction proceeds, entropy increases as the energy stored in the dry wood and leaves are used up as fuel to create the fire which produces low quality light and warmth.
2. This reaction is a classic example of an exothermic reaction. Exothermic reactions are characterized with the presence of heat and light in the products. Combustion reactions are always exothermic in nature.
3. Catalyst are substances that are used to speed up reactions by lowering the activation requirement. Catalysts aren't consumed in the reaction and can still be chemically retrieved afterwards. In this situation, the leaves cannot be retrieved after the reaction ends. The leaves speed up the heating of the wood but it does not behave as a catalyst.
Answer:

Explanation:
The elastic potential energy of a spring is given by
, where
is the spring constant of the spring and
is displacement from point of equilibrium.
When released, this potential energy will be converted into kinetic energy. Kinetic energy is given by
, where
is the mass of the object and
is the object's velocity.
Thus, we have:

Substituting given values, we get:

That's called the "Cosmic Microwave Background". (CMB)
It was discovered in 1965, and its discoverers were awarded
the Nobel Prize in Physics in 1978.
Answer:
C
Explanation:
An element is a pure substance that can not be broken down into anything simpler
A compound in also a pure substance held together in fixed proportion through chemical bonds
Answer:
The Principle of Progression
(I searched it up since I never learned this)
Explanation:
The principle of progression states that a person should start slowly and increase exercise gradually. Since Mandy is just getting started on her exercise routine, she should begin with a few workouts over a large span of time, then work her way up so she can do more workouts in a shorter span of time.