According to the law of conservation of energy, A) an object loses most of its energy as friction. B) the total amount of energy for a system stays the same. C) the potential energy of an object is always greater than its kinetic energy. D) the kinetic energy of an object is always greater than its potential energy.

Answer:

Force is must to change the velocity of an object. Force is always equal to the mass of the object times its acceleration.

Explanation:

From the second law of Newton, it  states that the force is the product of mass of an object and its acceleration. Here, when the bowling ball is rolling across a flat surface, frictional force acts on it which oppose the motion of the ball and causes deceleration of the ball. This is an example of rolling friction. Acceleration of the bowling ball depends directly to the force of friction and indirectly to its mass.

Answer;

A dense substance that is hard and incompressible

Explanation;

• Crystals are solids that are made up of particles such as molecules, atoms or ions, which are arrange in a highly ordered microscopic structure, forming a crystal lattice which extends in all directions.
• Examples of crystals include quartz, that is made up of silicon (iV) oxide molecules that are arranged in a lattice,table salt is another example that is made up of sodium and chloride ions that are arranged in a lattice
• Crystals are very ordered, they may be made up of atoms of the same elements or atoms of different elements such as in the case of table salt.

Answer: Option (c) is the correct answer.

Explanation:

When energy is supplied to an electron then on absorption of energy it tends to move from a lower energy level to higher energy level.

And, when this electron moves from higher energy level to lower energy level then excess of energy absorbed by it is released in the form of visible light or radiation.

This emission of energy is also responsible for imparting color to a compound.

Thus, we can conclude that electron gains energy when an electron moves to a higher energy level.

Answer:

The electrons in an atom exist in various energy levels. When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released (often as light).

Explanation:

The electrons in an atom exist in various energy levels. When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released (often as light).