1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Reika [66]
3 years ago
8

A group of electrons revolving around a nucleus forms an electron ____

Chemistry
1 answer:
Elanso [62]3 years ago
4 0

Answer:

Electron shell

Explanation:

You might be interested in
How many carbon atoms are in 7.05 moles of pyridine
NemiM [27]
First, it is best to know the chemical formula of pyridine which is C5H5N. To determine the number of carbon atoms present in pyridine, multiply 7.05 mol C5H5N with 5 mol C/ 1 mol C5H5N which then results to 35.35 mol of carbon. Then, multiply the answer to Avogadro's number which is 6.022x10^23 atoms. It is then calculated that the number of carbon atoms in 7.05 moles of pyridine is 2.12x10^25 atoms. 
5 0
3 years ago
Read 2 more answers
A very hot cube of copper metal (32.5 g) is submerged into 105.3 g of water at 15.4 0C and it reach a thermal equilibrium of 17.
zysi [14]

Answer:

The initial temperature of the metal is 84.149 °C.

Explanation:

The heat lost by the metal will be equivalent to the heat gain by the water.  

- (msΔT)metal = (msΔT)water

-32.5 grams × 0.365 J/g°C × ΔT = 105.3 grams × 4.18 J/g °C × (17.3 -15.4)°C

-ΔT = 836.29/12.51 °C

-ΔT = 66.89 °C

-(T final - T initial) = 66.89 °C

T initial = 66.89 °C + T final

T initial = 66.89 °C + 17.3 °C

T initial = 84.149 °C.

7 0
3 years ago
About 75% of living matter is made up of which two essential chemicals?
lions [1.4K]

calcium,phosphorus,potassium,and sulfer

3 0
3 years ago
Read 2 more answers
What is the molar out of a solution that contains 33.5g of CaCl2 in 600.0mL of water
omeli [17]

Answer:

Here's what I got.

Explanation:

Interestingly enough, I'm not getting

0.0341% w/v

either. Here's why.

Start by calculating the percent composition of chlorine,

Cl

, in calcium chloride, This will help you calculate the mass of chloride anions,

Cl

−

, present in your sample.

To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that

1

mole of calcium chloride contains

2

moles of chlorine atoms.

2

×

35.453

g mol

−

1

110.98

g mol

−

1

⋅

100

%

=

63.89% Cl

This means that for every

100 g

of calcium chloride, you get

63.89 g

of chlorine.

As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every

100 g

of calcium chloride, you get

63.89 g

of chloride anions,

Cl

−

.

This implies that your sample contains

0.543

g CaCl

2

⋅

63.89 g Cl

−

100

g CaCl

2

=

0.3469 g Cl

−

Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in

100 mL

of this solution.

Since you know that

500 mL

of solution contain

0.3469 g

of chloride anions, you can say that

100 mL

of solution will contain

100

mL solution

⋅

0.3469 g Cl

−

500

mL solution

=

0.06938 g Cl

−

Therefore, you can say that the mass by volume percent concentration of chloride anions will be

% m/v = 0.069% Cl

−

−−−−−−−−−−−−−−−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.

.

ALTERNATIVE APPROACH

Alternatively, you can start by calculating the number of moles of calcium chloride present in your sample

0.543

g

⋅

1 mole CaCl

2

110.98

g

=

0.004893 moles CaCl

2

To find the molarity of this solution, calculate the number of moles of calcium chloride present in

1 L

=

10

3

mL

of solution by using the fact that you have

0.004893

moles present in

500 mL

of solution.

10

3

mL solution

⋅

0.004893 moles CaCl

2

500

mL solution

=

0.009786 moles CaCl

2

You can thus say your solution has

[

CaCl

2

]

=

0.009786 mol L

−

1

Since every mole of calcium chloride delivers

2

moles of chloride anions to the solution, you can say that you have

[

Cl

−

]

=

2

⋅

0.009786 mol L

−

1

[

Cl

−

]

=

0.01957 mol L

−

This implies that

100 mL

of this solution will contain

100

mL solution

⋅

0.01957 moles Cl

−

10

3

mL solution

=

0.001957 moles Cl

−

Finally, to convert this to grams, use the molar mass of elemental chlorine

0.001957

moles Cl

−

⋅

35.453 g

1

mole Cl

−

=

0.06938 g Cl

−

Once again, you have

% m/v = 0.069% Cl

−

−−−−−−−−−−−−−−−−−−−

In reference to the explanation you provided, you have

0.341 g L

−

1

=

0.0341 g/100 mL

=

0.0341% m/v

because you have

1 L

=

10

3

mL

.

However, this solution does not contain

0.341 g

of chloride anions in

1 L

. Using

[

Cl

−

]

=

0.01957 mol L

−

1

you have

n

=

c

⋅

V

so

n

=

0.01957 mol

⋅

10

−

3

mL

−

1

⋅

500

mL

n

=

0.009785 moles

This is how many moles of chloride anions you have in

500 mL

of solution. Consequently,

100 mL

of solution will contain

100

mL solution

⋅

0.009785 moles Cl

−

500

mL solution

=

0.001957 moles Cl

−

So once again, you have

0.06938 g

of chloride anions in

100 mL

of solution, the equivalent of

0.069% m/v

.

Explanation:

i think this is it

8 0
3 years ago
The independent variable has control and affects the
Stella [2.4K]

Answer:

The independent variable is the condition that you change in an experiment. It is the variable you control.

Explanation:

It is called independent because its value does not depend on and is not affected by the state of any other variable in the experiment. Sometimes you may hear this variable called the "controlled variable" because it is the one that is changed.

3 0
3 years ago
Read 2 more answers
Other questions:
  • In Part A, you found the amount of product (2.60 mol P2O5 ) formed from the given amount of phosphorus and excess oxygen. In Par
    11·1 answer
  • A chemist must prepare 400 mL of 1.00M aqueous aluminum sulfate working solution. He'll do this by pouring out 1.82 mol/L aqueou
    6·2 answers
  • If the frequency of a wave is small the wavelength would be _____, and the energy would be______.
    9·1 answer
  • Butter has a specific gravity of 0.86. What is the mass of 2.15 L of butter?
    12·1 answer
  • An example of a physical change is A) cooking an egg. B) folding paper into a frog. C) rusting iron in an old bicycle. D) reacti
    5·2 answers
  • 2. During asexual reproduction in paramecia, a single paramecium becomes two new
    10·1 answer
  • What does electric current measure?
    11·2 answers
  • .In a _____ relationship one variable increases and a second variable increases proportionally,
    13·1 answer
  • Reaction:<br> HCI + NaOH -&gt;<br> NaCl + H20
    8·1 answer
  • Based on your observations, do you think any of the samples are the same substance?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!