Because they do. In fact, you can't get ANYTHING done without some energy changes involved.
Chemical bonds always break in chemical reactions, causing changes in energy.
There will always be changes in one of the reactants. In some chemical reactions, one of the chemicals works as a catalyst to encourage a reaction between two or more chemicals but does not change during the reaction.
electrons are always involved in chemical reactions. how they are positioned which atom they are located if they are sharing paired unpaired etc.
The combination of two elements (a metal and a nonmetal) is always a redox reaction.
Two types of energy changes that can occur in a chemical reaction are (1) endothermic and (2) exothermic. Endothermic is where energy is added to the system and exothermic is where energy is given off by the system.
no
Chemical bonds always break in chemical reactions, causing changes in energy.
Chemical bonds always break in chemical reactions, causing changes in energy.
Chemical bonds always break in chemical reactions, causing changes in energy.
There will always be changes in one of the reactants. In some chemical reactions, one of the chemicals works as a catalyst to encourage a reaction between two or more chemicals but does not change during the reaction.
always.
There are many different possible property changes in a chemical change. You must post the specific reaction for anyone to tell you exactly.
yes all changes involve exchange in energy
electrons are always involved in chemical reactions. how they are positioned which atom they are located if they are sharing paired unpaired etc.
They're both physical changes. Phase changes are always physical changes. Chemical changes only involve chemical reactions - a change in the identity of the substance. That's why phase changes are physical changes. Ice cream remains ice cream when it melts.
The combination of two elements (a metal and a nonmetal) is always a redox reaction.
Two types of energy changes that can occur in a chemical reaction are (1) endothermic and (2) exothermic. Endothermic is where energy is added to the system and exothermic is where energy is given off by the system.