Answer:
volume of 
Explanation:
Firstly balance the given chemical equation,

From the given balance equation it is clearly that,
2 mole of Li gives 1 mole of H2 gas
⇔
⇔
⇔
hence
3 mole of Li will give 1.5 mole H2 gas
therefore volume of gas produced from 3 mole Li at 
volume of H2=33.6 litre
Answer: Mixture
Explanation:
Element is a pure substance which is composed of atoms of similar elements.
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. Example: Air which conatins a mixture of
,
,
and 
The most appropriate word among the group of answer choices to fill in the blank is: a. Random sample surveys.
Sampling can be defined as a process used to collect or select data (objects, observations, or individuals) from a larger statistical population using specific procedures.
The various types of sampling used by researchers includes the following;
A random sample survey is also referred to as a simple random sample (SRS) and it can be defined as a sampling technique that involves randomly selecting a subset of a larger population. Also, any result obtained through the use of a random sample survey can be generalized and applied to a larger population.
In conclusion, scientists and researchers prefer random sample surveys because their results can be generalized to a larger population.
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