Hey there!:
Molar mass H3PO4 = <span>97.9952 g/mol
Atomic Masses :
H = </span><span>1.00794 a.m.u
</span>P = <span>30.973762 a.m.u
</span>O = 15.9994 a.m.u<span>
H % = [ ( 1.00794 * 3 ) / </span> 97.9952 ] * 100
H% = <span>3.0857 %
P % = [ ( </span>30.973762 * 1 ) / 97.9952 ] * 100
P% = <span>31.6074 %
O % = [ ( </span>15.9994 * 4 ) / 97.9952 ] * 100
O% = <span>65.3069 %
Hope this helps!</span>
Answer:
Explanation:
To solve this problem, we must understand the relationship between mass of a substance and the number of atoms.
Atoms are the smallest indivisible particles of any matter. A substance can be made up of several number of atoms in their space.
The mass of any substance is a function of the amount of atoms its contains.
The mass of a substance is related in chemistry to the amount of atoms its contains using the parameter called the number of moles.
A mole is the amount of substance that contains the Avogadro's number of particles. This number is 6.02 x 10²³ particles. The particles here can be protons, neutrons, electrons, atoms e.t.c.
Now,
Number of moles =
Molar mass of copper = 63.6g/mole
Number of moles = = 0.03mole
Since 1 mole of a substance contains 6.02 x 10²³atoms
0.03 mole of copper will contain 0.03 x 6.02 x 10²³atoms
= 1.89 x 10²² atoms
He needs to add 1.89 x 10²² atoms to make 2g of the sample.
I know for number 4 the answer is c, sorry I can't help with the others.
I believe the answer is The Dolphins.
In their Cooperative hunting, The dolphins requires five of its members to form of barrier while one or two of them are herding (Driving) their preys toward the barriers. And each dolphins will always play the same role in their group just like what we see in a football team.
The atomic number of copper is 29.
Hope this helps and if it does, don't be afraid to rate my answer as well as maybe give it a "Thanks"? (Or even better a "Brainliest"). And if it’s not correct, I am sorry for wasting your time, and good luck finding the correct answer :)