Answer: two or more different pure substances, which may be elements or compounds.
Explanation:
The term varieties of matter is kind of ambiguos since it is not defined.
The best approach to the question is to think of matter as it can be classified into to kinds: pure substaces and mixtures.
Elements and compounds are pure substances.
Elements are pure substances constituted by only one kind of atoms. An element cannot be divided into simpler substances either by physical or chemical media.
A compound is a chemical combination of two or more different elements. A compound can be divided into simpler substances by chemical reactions, but not by physical media. The properties of compounds are different of those of the elements of which they are constituted. The composition of a compoind (ratio among its elements) is fixed.
A mixture is the physical combination of two or more pure substances (either different elements or compounds) which can be mixed in any proportion. This is, its composition is variable. The substances that form the mixture can be separated by physical media.
1) reactants: Ca + O2 (g)
2) Unbalanced equation: Ca + O2 (g) -> CaO
3) Balanced equation: 2Ca + O2 (g) -> 2CaO
Answer: The tree died 9709.46 years before.
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
a) to find rate constant
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) to know the age
The tree died 9709.46 years before.
<span>One reaction takes place in less time than the other.</span>
Answer:
D.+1°e symbol represents a type of radiation that has the same mass as an electron and a positive charge.
