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nika2105 [10]
3 years ago
10

Can someone help, please ??

Chemistry
2 answers:
Yuri [45]3 years ago
8 0
13. The periodic table was discovered by Dalton.
14.NaCl is sodium chloride
Zinaida [17]3 years ago
5 0
Number 13 is D. Mendeleev. He was a Russian chemist and inventor who formulated the periodic table.
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Can someone answer #6 also please show work!
Andreas93 [3]
276mph that is easy because you times 11.5 with 24 which is the total number of hours per day
8 0
4 years ago
Read 2 more answers
To gain an idea as to how many atoms are in a gram or so of copper, use the larger balance
anygoal [31]

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  = \frac{mass}{molar mass}

          Molar mass of copper  = 63.6g/mole

         Number of moles  = \frac{2}{63.6}  = 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.

7 0
3 years ago
0.513 mol Al2O3 = g Al2O3
Dovator [93]

Answer:

Molar mass (M) = mass(m) / number of moles (n)

To find the mass of Al2O3 first calculate it's molar mass

thus

M(Al2O3) = (27×2) + (16 × 3)

= 54 + 48

= 102g/mol

Mass of Al2O3 = molar mass × number of moles

= 102 × 0.513

= 52.326g of Al2O3

Hope this helps

6 0
3 years ago
A room that is 500 cm x 400 cm x 250 cm contains 65 kg of air. Determine the volume of air in the room and its density.
seropon [69]

Answer:

1.3g/L is the density of the air

Explanation:

The room is full of air, the space that the air occupy is:

500 cm x 400 cm x 250 cm = 5.00x10⁷ cm³

The density of a substance is defined as the ratio between the mass of the substance and the space that occupy. We can express the density of air in g/L:

<em>Grams air:</em>

65 kg  * (1000g / 1kg) = 65000g

<em>Liters:</em>

5.00x10⁷ cm³ * (1L / 1000cm³) = 50000L

<em>Density:</em>

65000g / 50000L =

<h3>1.3g/L is the density of the air </h3>
7 0
3 years ago
A homogeneous mixture is also called _______________. a solution. an element. a pure substance. a heterogeneous mixture. a compo
inessss [21]
A solution is right answer.
6 0
4 years ago
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