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3 years ago

Which of the following groups contains mostly radioactive elements?

Chemistry

2 answers:

Blizzard [7]3 years ago

6 0

Answer:

Inner transition metals

Explanation:

The inner transition metals are also known as rare earth metals. The rare earth metals includes Lanthanide and Actinide Series of the periodic table. The elements with atomic numbers 89 to 103 are placed in the third group of the periodic table are Actinides. Examples are uranium and plutonium. These elements are with high oxidation number are radioactive elements. Thus, the inner transition metals are radioactive elements.

lukranit [14]3 years ago

6 0

Answer:

inner transition metals

Explanation:

The inner transition metals consists mostly of the f-block elements. They comprise of lanthanides and actinides. Many of them are radioactive because they possess atomic numbers greater than 82, hence their nuclei are unstable. Many of them are synthetic elements hence they are highly radioactive with very short half lives.

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3 years ago

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Lithium has two stable isotopes with masses of 6.01512 amu and 7.01600 amu. The average molar mass of Li is 6.941 amu. What is t

Dvinal [7]

Answer : The percent abundance of Li isotope-1 and Li isotope-2 is, 6.94 % and 93.1 % respectively.

Explanation :

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

Let the fractional abundance of Li isotope-1 be 'x' and the fractional abundance of Li isotope-2 will be '100-x'

For Li isotope-1 :

Mass of Li isotope-1 = 6.01512 amu

Fractional abundance of Li isotope-1 = x

For Li isotope-2 :

Mass of Li isotope-2 = 7.01600 amu

Fractional abundance of Li isotope-2 = 100-x

Average atomic mass of Li = 6.941 amu

Putting values in equation 1, we get:

$6.941=[(6.01512\times x)+(7.01600\times (100-x))]$

By solving the term 'x', we get:

$x=694.048$

Percent abundance of Li isotope-1 = $\frac{694.048}{100}=6.94\%$

Percent abundance of Li isotope-2 = 100 - x = 100-6.94 = 93.1 %

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3 years ago

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Ira Lisetskai [31]

Answer:

Solar Power, HEP (Hydroelectric Power), Wind Power, etc...

Explanation:

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3 years ago

Which statement about Earth's core helps explain Earth's magnetic field?

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Answer:

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3 years ago

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What is the empirical formula of a compound that is 24.42 % calcium, 17.07 % nitrogen, and 58.5% oxygen?

REY [17]

Answer:

$CaN_{2} O_{6}$

Explanation:

When calculating an empirical formula from percentages, assume you have a 100g sample. This allows you to convert the percentages directly to grams, because X % of 100g is X grams.

So:

24.42 % = 24.42 g Ca, 17.07% = 17.07g N, 58.5% = 58.5g O

The next step is to divide each mass by their molar mass to convert your grams to moles.

24.42/40.08 = 0.6092 mol

17.07/14.01 = 1.218 mol

58.85/15.99 = 3.680 mol

Then you will divide all of your mol values by the SMALLEST number of moles. This gives you whole numbers that are the mole ratio (subcripts) of the empircal formula.

0.6092 mol/0.6092 mol = 1

1.218 mol/0.6092 mol = 2

3.680 mol/0.6092 mol = 6

So the empirical formula is $CaN_{2} O_{6}$

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3 years ago