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Scilla [17]
3 years ago
8

(5 x 10-21) - (4 x 10-22)​

Chemistry
2 answers:
Alborosie3 years ago
6 0

Answer:

11

Explanation:

5×10-21 = 29

4×10-22 = 18

29 - 18 = 11

Ivanshal [37]3 years ago
5 0

Answer:

29     and      18

Explanation:

You might be interested in
Why might genetically identical twins have different phenotype
KIM [24]

Answer:

They may have different phenotypes because of differences in their environments, such as nutrition and healthcare. Why might genetically identical twins have different phenotypes?  Any genes on the same chromosome could be linked genes, whereas only genes on sex chromosomes can be sex-linked genes.

Explanation:

8 0
3 years ago
8. Balance the following nuclear equations:<br> ^65/30Ca -&gt; ^65/29Sc +_______
a_sh-v [17]

Explanation:

          ⁶⁵₃₀Ca   →   ⁶⁵₂₉Sc  +   ⁿₓH

The reaction above is nuclear reaction.

In a nuclear reaction, the mass number and atomic number must be conserved.

The mass number is the superscript before the atom

Atomic number is the subscript before the atom

  Conserving mass number:

       65 = 65 + n

        n = 0

   conserving atomic number:

    30 = 29 + x

     x = 1

The unknown atom is a positron i.e a positively charged electron:   ⁰₁e

              ⁶⁵₃₀Ca   →   ⁶⁵₂₉Sc  +  ⁰₁e

learn more:

Transmutation brainly.com/question/3433940

#learnwithBrainly

3 0
3 years ago
Dolomite is a mixed carbonate of calcium and magnesium. Calcium and magnesium carbonates both decompose upon heating to produce
Setler79 [48]

Answer:

72.03 %

Explanation:

Total mass of dolomite = 9.66 g

Let the mass of Magnesium carbonate = x g

The mass of calcium carbonate = 9.66 - x g

Calculation of the moles of Magnesium carbonate as:-

Molar mass of Magnesium carbonate = 122.44 g/mol

The formula for the calculation of moles is shown below:

moles = \frac{Mass\ taken}{Molar\ mass}

Thus,

Moles= \frac{x\ g}{84.3139\ g/mol}=\frac{x}{84.3139}\ mol

Calculation of the moles of calcium carbonate as:-

Molar mass of calcium carbonate = 100.0869 g/mol

Thus,

Moles= \frac{9.66 - x\ g}{100.0869\ g/mol}=\frac{9.66 - x}{100.0869}\ mol

According to the reaction shown below:-

MgCO_3\rightarrow MgO+CO_2

CaCO_3\rightarrow CaO+CO_2

In both the cases, the oxides formed from the carbonates in the 1:1 ratio.

So, Moles of MgO = \frac{x}{84.3139}\ mol

Molar mass of MgO = 40.3044 g/mol

Thus, Mass = Moles*Molar mass = \frac{x}{84.3139}\times 40.3044 \ g

Moles of CaO = \frac{9.66 - x}{100.0869}\ mol

Molar mass of CaO = 56.0774 g/mol

Thus, Mass = Moles*Molar mass = \frac{9.66 - x}{100.0869}\times 56.0774 \ g

Given that total mass of the oxide = 4.84 g

Thus,

\frac{x}{84.3139}\times 40.3044 +\frac{9.66 - x}{100.0869}\times 56.0774=4.84

\frac{40.3044x}{84.3139}+56.0774\times \frac{-x+9.66}{100.0869}=4.84

-694.1618435x+45673.48749\dots =40843.38968\dots

x=\frac{4830.09780\dots }{694.1618435}

x=6.9582

Thus, the mass of Magnesium carbonate = 6.9582 g

\%\ mass=\frac{Mass_{MgCO_3}}{Total\ mass}\times 100

\%\ mass=\frac{6.9582}{9.66}\times 100=72.03\ \%

3 0
3 years ago
Calculate number of moles in 10.6g of sodium carbonate
natulia [17]
<em>m Na₂CO₃: 23g×2 + 12g + 16g×3 = 106 g/mol</em>
------------------------------
1 mol ------- 106g 
X ------------ 10,6g
X = 10,6/106
<u>X = 0,1 mol Na₂CO₃</u>
7 0
3 years ago
In a _________the molecules are very close together
Maurinko [17]
Is a solid because liquids are not is not that close and gas is very far apart.
4 0
3 years ago
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