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IrinaVladis [17]
3 years ago
8

Which element is located in period 4?

Chemistry
1 answer:
Lena [83]3 years ago
6 0

Answer:

i beleive iron

Explanation:

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Sodium oxide is the product

Explanation:

4Na+O2->2Na2O

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Which is not an observation?
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A particular oral contraceptive contains 0.038 mg of ethinyl estradiol in each pill. The formula of this compound is C20H24O2. H
Ray Of Light [21]

<u>Answer:</u> The number of molecules of ethinyl estradiol present in one pill are 7.71\times 10^{16}

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}

Given mass of ethinyl estradiol = 0.038 mg = 3.8\times 10^-5}g    (Conversion factor: 1 g = 1000 mg)

Molar mass of ethinyl estradiol (C_{20}H_{24}O_2)=[(20\times 12)+(24\times 1)+(2\times 16)]=296g/mol

Putting values in above equation, we get:

\text{Moles of ethinyl estradiol}=\frac{3.8\times 10^{-5}g}{296g/mol}=1.28\times 10^{-7}mol

According to mole concept:

1 mole of a compound contains 6.022\times 10^{23} number of molecules

So, 1.28\times 10^{-7}mol of ethinyl estradiol will contain = (1.28\times 10^{-7}\times 6.022\times 10^{23})=7.71\times 10^{16} number of molecules

Hence, the number of molecules of ethinyl estradiol present in one pill are 7.71\times 10^{16}

5 0
3 years ago
What are the components needed in order for an experiment to be valid? Identify these components in the following experiment: A
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He needs to give plants the same conditions besides food: same water (amount), same light exposure, same temperature, etc.

He needs to choose a quantitative way to measure how much the plants grew, like mass or length.
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What is the product of the reduction of an aldehyde?
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5 0
3 years ago
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