Which property of an atom's structure was used to organize the periodic table?

Find the number of moles of argon in 364 grams of argon.

serg [7]

Answer:D. 9.1 mole Ar

Explanation:

364 g Ar x 1 mole Ar / 40 g Ar

= 9.1 moles Ar

3 0

3 years ago

What effect does pneumonia have on the diffusion of O2 and CO2 across the membranes in the lungs? a. slows diffusion b. complete

GarryVolchara [31]

Answer:

a. slows diffusion

Explanation:

Gas exchange on respiratory surfaces in the body (the lungs) occurs through a process known as diffusion. Blood which is low in oxygen and high in carbondioxide (carried from cells) goes through an exchange in the lung's alveoli (where oxygen concentration is high and carbondioxide is low). The oxygen in the alveoli diffuses into the blood, while the carbondioxide in the blood diffuses into the alveoli. This diffusion is possible because of the concentration gradient across the membranes.

Pneumonia is the inflammation of the lungs due to injury or infection. Liquid (pus) accumulates in the alveoli (a natural immune response to the infection or injury), a condition known as pulmonary edema which makes it harder for gases to be exchanged between the blood and the alveoli, thereby making breathing difficult. This slows down diffusion and if the condition is severe enough, can cause a respiratory failure where oxygen levels in the blood are critically low and carbondioxide levels are very high.

5 0

2 years ago

Explain why gases condense when they are cooled

Sindrei [870]

We can explain this in a molecular level. We know that the difference between a gas and a liquid of the same composition is how fast their molecules are moving. So given a gas, their molecules are farther and faster when moving, but when they are cooled their bulk kinetic energy decreases. In other words their molecules start to move closer and move slower until it behaves more like a liquid molecule. This is the time when gases condense.

4 0

3 years ago

Read 2 more answers

Laura has 3 beakers. Each contain 200cm3 of colourless liquid. Describe how Laura could determine which beakers contain pure wat

vova2212 [387]

Answer:

Laura can look for a transparent and translucent liquid and hence determine which beaker has water and which has solution

Explanation:

Pure water is a compound that is transparent in color. However, a solution is a liquid mixture comprising of a solvent or a solute. The atoms of solute occupy space between the atoms of solvent and hence are said to dissolve in it. Water can be a solvent.

Thus, if the beaker has a transparent liquid in it, then it would be pure water while a beaker having a translucent liquid, then it would be a solution

6 0

3 years ago

The rock in a lead ore deposit contains 89 % PbS by mass. How many kilograms of the rock must be processed to obtain 1.5 kg of P

Zolol [24]

Answer:

Approximately 1.9 kilograms of this rock.

Explanation:

Relative atomic mass data from a modern periodic table:

Pb: 207.2;
S: 32.06.

To answer this question, start by finding the mass of Pb in each kilogram of this rock.

89% of the rock is $\rm PbS$ . There will be 890 grams of $\rm PbS$ in one kilogram of this rock.

Formula mass of $\rm PbS$ :

$M(\mathrm{PbS}) = 207.2 + 32.06 = 239.26\; g\cdot mol^{-1}$ .

How many moles of $\rm PbS$ formula units in that 890 grams of $\rm PbS$ ?

$\displaystyle n = \frac{m}{M} = \rm \frac{890}{239.26} = 3.71980\; mol$ .

There's one mole of $\rm Pb$ in each mole of $\rm PbS$ . There are thus $\rm 3.71980\; mol$ of $\rm Pb$ in one kilogram of this rock.

What will be the mass of that $\rm 3.71980\; mol$ of $\rm Pb$ ?

$m(\mathrm{Pb}) = n(\mathrm{Pb}) \cdot M(\mathrm{Pb}) = \rm 3.71980 \times 207.2 = 770.743\; g = 0.770743\; kg$ .

In other words, the $\rm PbS$ in 1 kilogram of this rock contains $\rm 0.770743\; kg$ of lead $\rm Pb$ .

How many kilograms of the rock will contain enough $\rm PbS$ to provide 1.5 kilogram of $\rm Pb$ ?

$\displaystyle \frac{1.5}{0.770743} \approx \rm 1.9\; kg$ .

5 0

3 years ago