Answer:
NaOH(aq) is a Base.
Explanation:
Those substances which give or release
ions in aqueous solution are called as the Arrhenius Bases.
In the aqueous solution, NaOH dissociates as follows -
↔ 
If it reacts with a strong acid HCl, the chemical equation for this reaction will be as follows -

Answer:
Helium, this noble gas has the least density at STP
Explanation:
Answer:
Compound
Explanation:
compound: Substance that is made up of more than one type of atom bonded together
mixture: a combination of two or more elements of compound which are not chemically bonded
Chemical properties is when a material undergoes a chemical change or reaction like a nail rusting and a physical change can be observed without changing the material like temperature, color, texture, odor,etc.
There are several ways of expressing concentration of solution. Few of them are listed below
1) mass percentage
2) volume percentage
3) Molarity
4) Normality
5) Molality
In most of the drugs, concentration is expressed either in terms of mass percentage or volume percentage. For, solid in liquid type systems, mass percentage is convenient way of expressing concentration, while for liquid in liquid type solutions, expressing concentration in terms of volume percentage is preferred. Present system is an example of liquid in liquid type solution
Here, concentration of H2O2 is given antiseptic = 3.0 % v/v
It implies that, 3ml H2O2 is present in 100 ml of solution
Thus, 400 ml of solution would contain 4 X 3 = 12 ml H2O2