so the reaction can get started
Increasing temperature provides molecules with more kinetic energy, increasing the likelihood of successful collisions to activate a reaction without the need for external energy input. As a result, the activation energy required decreases at higher temperatures, making the reaction more favorable and faster.
In fusion reactions, nuclei need to overcome the strong electromagnetic repulsion to merge and release energy, requiring high temperatures to achieve the necessary kinetic energy. In fission reactions, nuclei need to be bombarded by neutrons to induce a split, a process that can occur at lower temperatures.
Non-living objects like rocks, stationary objects, or inert gases do not require energy. Additionally, certain physical processes like diffusion or certain chemical reactions may occur spontaneously without the need for an external energy source.
There are many ways to convert one form of energy into another form. We do have to start with energy (or in the case of an atomic bomb, mass-energy) in order to make another form of energy because it is impossible to make energy out of nothing (as stated in the law of conservation of mass-energy). Since the human body runs on chemical energy, we do use some degree of chemical energy in everything we do - even thinking requires it, not just the movement of muscles. If I cut a rope that is holding up a weight, which then falls, I would then be converting gravitational potential energy to kinetic energy - although even then, some chemical energy would also be involved in moving my hand in order to cut the rope.
The minimum energy requirement for a collision to be successful depends on the specific reaction and molecules involved. Generally, colliding particles need to surpass the activation energy barrier to initiate a successful reaction. This energy is determined by the specific chemical bonds involved and the reaction mechanism.
Exothermic reactions need activation energy to start, but they also need it to keep going to build up heat. At the end of the reaction, the products have less energy than the reactants. This produces heat. In order for this to happen, the exothermic reaction needs activation energy.
exothermic reactions provide us with the energy we need to carry out daily activities
No. It requires an energy input (the activation energy) before it can proceed. For some reactions the energy needed can be as low as simply heat from the room and others need thousands of Watts of electrical power.
An exothermic reaction releases energy, usually to the surroundings. There is a net loss of energy from the reactants. However, exothermic reactions also need a little energy to get started, but this is less than the eventual amount given out. An endothermic reaction takes in energy, also usually from the surroundings. There is a net gain of energy into the reactions. Again, a little energy is lost, but this is hardly anything compared to the amount taken in.
All chemical reactions need a certain amount of activation energy to get started.
Ipso facto. An endothermic reaction "absorbs" energy (uses it to create high-energy bonds), so this must be constantly supplied from an external source. An exothermic reaction "releases" energy, and this energy can be used to continue the reaction until there are no reactants remaining.This is why stellar cores cannot fuse massive quantities of elements heavier than iron. The reactions are not self-perpetuating as they are absorbing energy rather than releasing it. A large, inert iron core is the result.
I wonder about a lot of things, yes.
Reactions in the body need a certain amount of energy, called activation energy. Most reactions don't take place because this activation energy is too high. The enzyme bonds to the molecule which diminguishes the activation energy, so the reaction can take place. These enzymes de-bond from the new formed molecule afterwards.
Exothermic reactions release energy (usually as heat) into the surrounding environment - endothermic reactions absorb energy from the surrounding environment. Note that exothermic reactions are capable of turning into runaway reactions as the heat of reaction often speeds up the rate of reaction (releasing more heat, etc). Endothermic reactions are, usually, self moderating as a limited amount of energy is capable of being drawn from the surrounding environment.
Living things have cellular reactions which involve both reactions in the process. Endothermic reactions help the body conserve energy or contain it. Exothermic reactions help the body produce energy.
An 'exothermic' reaction gives of energy, and an 'endothermic' reaction absorbs energy.
Chemical reactions in living organisms require a source of energy to start. This energy is typically obtained from molecules such as ATP. Additionally, enzymes play a critical role in catalyzing these reactions by lowering the activation energy required for the reaction to occur.