A compound is a pure substance formed by the chemical combination of two or more different elements.
A compound may be splitted into simpler substances by chemical reactions, and has different properties to those of the elements that form it.
The composition of a compound is fixed: every piece of a compound has the same kind of atoms, bonded in the same way and proportion.
Some examples of compounds are H₂O, NaCl, H₂O₂, CH₃COOH. As you see, they have a chemical formula which states the kind and number of the atoms that form them.
They are different to mixtures, which are formed by two or more compounds, in a variable proportion, and can be separated by physical media. Some examples of mixtures are the solutions (e.g. NaCl dissolved in H₂O), and some solid mixtures (e.g. a mixture of marbles and sand).
Answer:
Because it keeps track of all the elements
This one is beta decay (the -1 subscript tells us that)
Characteristics of acid
-It tastes sour
-It reacts with metals and carbonates
-It turns blue litmus paper red
Characteristics of base
-It tastes bitter
-It feels slippery
-It turns red litmus paper blue.
