Atomic mass of N from periodic table is 14 amu so atomic mass of N₂ will be 2 * 14 = 28 amu
This means that every mole of N₂ has mass equal to 28 g
C is the answer because a and b are definitions for mass and volume and a doesn’t have to do with density
Answer:
Selenium has 36 valence electrons.
After one half life initial amounts gets half so :-
- First half life :- 350÷2 = 175 grams
- second half life :- 175 ÷2 = 87.5 grams
- third half life :- 87.5 ÷2 = 43.75 grams
so at last of third half life amount left = 43.75 grams
each time amount get half
ask ure doubt freely in comments
Answer:
The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.
Explanation:
The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:
n = 1.375x10⁻⁵ mol
The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):
1.375x10⁻⁵ mol _________ 19.9 units
x _________ 25.2 units
x = 1.741x10⁻⁵mol
Finally, we can calculate the Cu²⁺ concentration :
C = 1.741x10⁻⁵mol / 0.025 L
C = 6.964x10⁻⁴ M