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Finger [1]
3 years ago
15

How much time would it take for 12000 atoms of nitrogen-13 (half-life is 7.13 s) to decay to 750 atoms?

Chemistry
1 answer:
Rainbow [258]3 years ago
8 0
<h3>Answer:</h3>

28.52 seconds

<h3>Explanation:</h3>

Initial number of atoms of Nitrogen 12,000 atoms

Half-life = 7.13

Number of atoms after decay = 750 atoms

We are required to determine the time taken for the decay.

Note that half life is the time taken for a radioactive isotope to decay to a half of its original amount.

Using the formula;

Remaining amount = Initial amount × (1/2)^n , where n is the number of half lives

In our case;

750 atoms = 12,000 atoms × (1/2)^n

0.0625 = 0.5^n

n = log 0.0625 ÷ log 0.5

n = 4

But, 1 half life =7.13 seconds

Therefore;

Time taken = 7.13 seconds × 4

                  = 28.52 seconds

Therefore, the time taken for 12,000 atoms of nitrogen to decay to 750 atoms is 28.52 seconds

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Answer:

An atom with 1 valence electron and an atom with 7 valence electrons

Explanation:

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The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.

For example:

In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive.

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4 0
3 years ago
What is the percent composition by mass of oxygen in Ca(NO3)2 (gram-formula= 164 g/mol)?
Neko [114]
To find this, we will use this formula:

Molar mass of element
------------------------------------ x 100
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So, first lets calculate the mass of the compound as a whole. We use the atomic masses on the periodic table to determine this.

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O6 (there are six nitrogens: 3 times 2): 95.994 g/mol

When we add all of those numbers up together, we get 164.086. That is the molar mass for the whole compound. However, we are trying to figure out what percent of the compound oxygen makes up. From the molar mass, we know that 95.994 of the 164.086 is oxygen. Lets plug those numbers into our equation!

95.994
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When we divide those two numbers, we get .585. When we multiply that by 100, we get 58.5.

So, the percent compostition of oxygen in Ca(NO3)2, or, calcium nitrate, is 58.5%.
5 0
3 years ago
Lab safety is not only important in the classroom, but it is also important to follow
defon

Answer:

Follow safety measures and safety rules to avoid any accident.

Explanation:

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2. Safety rules should always be followed when conducting an experiment at any place such as at home, class room and laboratory etc in order to avoid any accident.

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4 years ago
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Will you please tell about which model are you talking about? So, that I can help you because your seems to be incomplete.
6 0
3 years ago
Which is the correct Lewis dot structure of C2H2
denpristay [2]

The correct answer is A

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3 0
3 years ago
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