Substances have different tendencies to donate or accept electrons. When a really good donor meets a great acceptor, the chemical reaction releases a lot of energy. Oxygen (O2) is the best electron acceptor and is used in many aerobic reactions (reactions with oxygen). Hydrogen gas (H2) is a good electron donor.
When O2 and H2 are combined, along with a catalyst, water (H2O) is formed. This example of a redox reaction can be written like this:

(2) 2 - 7 - 18 - 7 does, because the electron from the L shell jumped to the N shell, which requires energy.
The rest of them are either different types of atoms (different elements) or are not the excited state (ground state)
Answer:
Chemical
Explanation:
Macromolecules are part of the chemical components of cells. For example, DNA, proteins, and lipids.
Cells of similar types/function form tissues. Different types of tissues interact together to form organs. Organs form a common function.
A is a model of a decomposition reaction
Use the formula
first step:
Use the formula
molarity= mole/liter
change ml to l
plug in data
to get .1=mole/.25 or .1M*.25liter
which =.025 moles
then divide .025 moles by two because there are two OH in Sr(OH)2
then multiply that by 265.76 (the molar mass of water)
.0125*265.76
which is 3.32grams this is your answer
