Answer:
argon and helium
Explanation:
Argon and Helium is belongs to noble gas. Since novel gases are completely filled outer orbital. therefore they are erratic nature. Hence, noble gas are very stable as it neither except electron nor it denote due to it paired of electronic configuration.
Depending on the materials being welded, these atmospheric gases react with welding area and either it reduces the quality of the weld or make the welding more difficult.
Therefore, to protect welding area from atmospheric gases noble gases which are small in size are used.
Thus, argon and helium are used.
Answer:-
0.229 L
Explanation:-
Molar mass of AgBr = 107.87 x 1 + 79.9 x 1
=187.77 grams mol-1
Mass of AgBr = 150 grams
Number of moles of AgBr = 150 grams / 187.77 gram mol-1
= 0.8 mol
The balanced chemical equation is
NaBr (aq) + AgNO3 (aq)--> AgBr(s) + NaNO3(aq)
From the equation we can see that
1 mol of AgBr is produced from 1 mol of AgNO3.
∴ 0.8 mol of AgBr is produced from 1 x 0.8 / 1 = 0.8 mol of AgNO3.
Strength of AgNO3 = 3.5 M
Volume of AgNO3 required = Number of moles / strength
= 0.8 moles / 3.5
=0.229 L
Gravity is the force that keeps the planets in orbit.
An element is a pure substance that cannot be separated or divided into simpler substances by any method (physical or chemical). The four common elements in all the living organisms are carbon, oxygen, hydrogen, nitrogen.
Thus, the four elements that make up about 96 % of body matter are carbon, oxygen, hydrogen, nitrogen (c).
