<span>The law of conservation of energy states that energy can neither be created nor destroyed - it can only be converted from one form to another. It basically means that energy can't just appear, but has to be converted from existing energy; for example, the chemical energy in petrol is turned into electrical energy to power a car.Remember the total energy of universe is constant,,and no more energy can be drawn from out if we collect all universe's energy at a single point(its the big bang energy splitted during </span>
Answer:

Explanation:
We already know that the mass number of an atom is the sum of the number of protons and the number of neutrons.
So, the mass number of this isotope is;
Number of protons = 7
Number of neutrons = 8
Mass number = 7 + 8 = 15
Hence, the isotope is;

Answer:
The three types of organisms in an ecosystem are producers, consumers, and decomposers.
Producers get their energy by using sunlight to make their own food from water and carbon dioxide through photosynthesis.
Consumers get their energy by eating plants and animals for food as they cannot make their own food.
Decomposers get their energy by eating/scavenging and breaking down dead and decaying plant and animal bodies.
Hope that helps.
B the girls arm will act as a pulley