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2 years ago

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Calcium is a nontoxic metal that is used in supplements to maintain strong bones. Under high pressure conditions, over about 320

,000 atm, it has a simple cubic unit cell. How many atoms of Ca are present in each unit cell?

1 answer:

Lera25 [3.4K]2 years ago

4 0

Explanation:

It is known that in a simple cubic unit cell the atoms are only present at the corner of the unit cell. This means that there are in total 8 atoms present in a simple cubic unit cell.

Therefore, in one simple cubic unit cell sharing of one atom is only $\frac{1}{8}$ .

Hence, the total number of atoms in a unit cell will be as follows.

$8 \times \frac{1}{8}$ = 1

Thus, we can conclude that there is 1 calcium atom present in each unit cell.

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Which water source becomes polluted as it travels over the earth?

never [62]

Run off

Explanation:

Run-off are the water sources that becomes polluted as they travel over the earth surface.

Surface run-off are water that moves on the earth surface. This water is a component of the water cycle which usually originate from precipitation.

As the water moves through different terrain it comes into contact with different pollutants.
Some of these run-off travels through mines, waste disposal sites among others.
This leads to the contamination of this form of water as it moves through these earth materials.
They are the most polluted water

Learn more:

Ocean water brainly.com/question/6760255

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8 0

3 years ago

What two dose the transfer of light energy require

IrinaK [193]

Answer:

Magnetic fields and Electric fields

Explanation:

3 0

2 years ago

Part A: Three gases (8.00 g of methane, CH_4, 18.0g of ethane, C_2H_6, and an unknown amount of propane, C_3H_8) were added to t

myrzilka [38]

Explanation:

Part A:

Total pressure of the mixture = P = 5.40 atm

Volume of the container = V = 10.0 L

Temperature of the mixture = T = 23°C = 296.15 K

Total number of moles of gases = n

PV = nRT (ideal gas equation)

$n=\frac{PV}{RT}=\frac{5.40 atm\times 10.0 L}{0.0821 atm L/mol K\times 296.15 K}=2.22 mol$

Moles of methane gas = $n_1=\frac{8.00 g}{16 g/mol}=0.5 mol$

Moles of ethane gas = $n_2=\frac{18.0 g}{30 g/mol}=0.6 mol$

Moles of propane gas = $n_3$

$n=n_1+n_2+n_3$

$2.22=0.5 mol +0.6 mol+ n_3$

$n_3= 2.22 mol - 0.5 mol -0.6 mol= 1.12 mol$

Mole fraction of methane = $\chi_1=\frac{n_1}{n_1+n_2+n_3}=\frac{n_1}{n}$

$\chi_1=\frac{0.5 mol}{2.22 mol}=0.2252$

Similarly, mole fraction of ethane and propane :

$\chi_2=\frac{n_2}{n}=\frac{0.6 mol}{2.22 mol}=0.2703$

$\chi_3=\frac{n_3}{n}=\frac{1.12 mol}{2.22 mol}=0.5045$

Partial pressure of each gas can be calculated by the help of Dalton's' law:

$p_i=P\times \chi_1$

Partial pressure of methane gas:

$p_1=P\times \chi_1=5.40 atm\times 0.2252=1.22 atm$

Partial pressure of ethane gas:

$p_2=P\times \chi_2=5.40 atm\times 0.2703=1.46 atm$

Partial pressure of propane gas:

$p_3=P\times \chi_3=5.40 atm\times 0.5045=2.72 atm$

Part B:

Suppose in 100 grams mixture of nitrogen and oxygen gas.

Percentage of nitrogen = 37.8 %

Mass of nitrogen in 100 g mixture = 37.8 g

Mass of oxygen gas = 100 g - 37.8 g = 62.2 g

Moles of nitrogen gas = $n_1=\frac{37.8 g g}{28g/mol}=1.35 mol$

Moles of oxygen gas = $n_2=\frac{62.2 g}{32 g/mol}=1.94 mol$

Mole fraction of nitrogen= $\chi_1=\frac{n_1}{n_1+n_2}$

$\chi_1=\frac{1.35 mol}{1.35 mol+1.94 mol}=0.4103$

Similarly, mole fraction of oxygen

$\chi_2=\frac{n_2}{n_1+n_2}=\frac{1.94 mol}{1.35 mol+1.94 mol}=0.5897$

Partial pressure of each gas can be calculated by the help of Dalton's' law:

$p_i=P\times \chi_1$

The total pressure is 405 mmHg.

P = 405 mmHg

Partial pressure of nitrogen gas:

$p_1=P\times \chi_1=405 mmHg\times 0.4103 =166.17 mmHg$

Partial pressure of oxygen gas:

$p_2=P\times \chi_2=405 mmHg\times 0.5897=238.83 mmHg$

3 0

2 years ago

What is one way a pathogen can enter the body?

Ipatiy [6.2K]

I’m pretty sure it’s Nose

8 0

2 years ago

Read 2 more answers

Students conduct an experiment:

sweet-ann [11.9K]

Answer:

The balloon becomes inflated

Explanation:

The equation of the reaction between baking soda (sodium bicarbonate) and vinegar(ethanoic acid) is shown below;

NaHCO3 + HC2CH3O2 ------> NaC2H3O2 + H2O + CO2

The gas (CO2) evolved in the process leads to the inflation of the balloon dropped on the bottle in which the reaction is taking pace.

This observation provides evidence that a gas was really evolved in the reaction.

7 0

3 years ago