Answer:
It conducts electricity
It conducts heat
Water is needed for rusting
Explanation:
Metals refer to elements that are found towards the left hand side of the periodic table of elements. They are found in groups 1- 13 and few of them are also found at the bottom of groups 14 and 15.
Now these metal have certain properties that are general to all of them. two of these properties listed among the options in the question are;
i) They conduct electricity
ii) They conduct heat
These properties apply to all metals universally.
Rusting is an electrochemical reaction in which hydrated iron III oxide is formed. In the electrochemical reaction, water in intimately involved in the process. Hence; oxygen and water are required for rusting to take place.
Answer : The excess reactant in the combustion of methane in opem atmosphere is
molecule.
Solution : Given,
Mass of methane = 23 g
Molar mass of methane = 16.04 g/mole
The Net balanced chemical reaction for combustion of methane is,

First we have to calculate the moles of methane.
=
= 1.434 moles
From the above chemical reaction, we conclude that
1 mole of methane react with the 2 moles of oxygen
and 1.434 moles of methane react to give
moles of oxygen
The Moles of oxygen = 2.868 moles
Now we conclude that the moles of oxygen are more than the moles of methane.
Therefore, the excess reactant in the combustion of methane in open atmosphere is
molecule.
Answer:
C) 
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
The expression of the pH of the calculation of weak acid is:-
Where, C is the concentration = 0.5 M
Given, pH = 2.94
Moles = 0.100 moles
Volume = 1.00 L
So, 
C = 0.100 M


