Answer:
<u> Translation:</u>
Classify the following elements into metals, nonmetals, metalloids, or gases, noble
: fluorine, sulfur, nitrogen, chlorine, magnesium, helium, sodium, bromine, silicon, tellurium.
- Metals: magnesium and sodium.
- Nonmetals: fluorine, chlorine, bromine, sulfur and nitrogen.
- Metalloids: silicon and tellurium.
- Noble gases: helium.
Explanation:
Metals: They occupy the left and central areas of the Periodic Table; therefore, they constitute a majority group of the elements.
Nonmetals: They are located in the upper right region of the Periodic Table.
Within the Periodic Table, the metalloids lie diagonally from boron to polonium. Items above on the right are nonmetals, and items below on the left are metals.
The noble gases are located in group 18 of the Periodic Table.
There are exactly (a). 10.0 and (b). 28.0
Answer: 68
Explanation: u times them
Hi!
I'm not entirely sure about this so I'm sorry if I'm wrong but I think it would be helium.
Again in not entirely sure but i hope this helped you, i hope you have a great day, afternoon, or night!
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.