Copper has 29 electrons, and its electron configuration is:
1s2 2s2 2p6 3s2 3p6 3d10 4s1.
Therefore, copper has 1 valence electron.
Hope this helps~
Answer:
53.5g of NH4Cl
Explanation:
First, we need to obtain the number of mole of NH4Cl. This is illustrated below:
Volume = 0.5L
Molarity = 2M
Mole =?
Molarity = mole /Volume
Mole = Molarity x Volume
Mole = 2 x 0.5
Mole = 1mole
Now, let us convert 1mole of NH4Cl to gram. This is illustrated below:
Molar Mass of NH4Cl = 53.5g/mol
Number of mole = 1
Mass =?
Number of mole = Mass /Molar Mass
Mass = number of mole x molar Mass
Mass = 1 x 53.5
Mass = 53.5g
Therefore, 53.5g of NH4Cl is contained in the solution.
Answer:
Approximately
.
Explanation:
Note that both figures in the question come with four significant figures. Therefore, the answer should also be rounded to four significant figures. Intermediate results should have more significant figures than that.
<h3>Formula mass of strontium hydroxide</h3>
Look up the relative atomic mass of
,
, and
on a modern periodic table. Keep at least four significant figures in each of these atomic mass data.
Calculate the formula mass of
:
.
<h3>Number of moles of strontium hydroxide in the solution</h3>
means that each mole of
formula units have a mass of
.
The question states that there are
of
in this solution.
How many moles of
formula units would that be?
.
<h3>Molarity of this strontium hydroxide solution</h3>
There are
of
formula units in this
solution. Convert the unit of volume to liter:
.
The molarity of a solution measures its molar concentration. For this solution:
.
(Rounded to four significant figures.)
Answer:
0.719 moles of NH₃
Explanation:
Molar mass of ammonia 17 g/mol
Mass of amonia = 12.23 g
Mass / Molar mass = Moles
12.23 g / 17 g/mol = 0.719 moles
The answer would be D. The only minerals harder than corundum is diamond.