Joanne has to undergo a________ in order to repair her breasts.

The term “ average atomic mass “ is a ______average so is calculator different Lee from a normal average

hoa [83]

Average atomic mass of an element is a sum of the product of the isotope mass and its relative abundance.

For example: Chlorine has 2 isotopes with the following abundances

Cl(35): Atomic mass = 34.9688 amu; Abundance = 75.78%

Cl(37): Atomic mass = 36.9659 amu; Abundance = 24.22 %

Average atomic mass of Cl = 34.9688(0.7578) + 36.9659(0.2422) =

= 26.4993 + 8.9531 = 35.4524 amu

Thus, the term “ average atomic mass “ is a weighted average so it is calculated differently from a normal average

3 0

3 years ago

A chemist prepares a sample of helium gas at a certain pressure, temperature and volume and then removes all but a fourth of the

cupoosta [38]

Answer:

The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.

Explanation:

Pressure in the container is P and volume is V.

Temperature of the helium gas molecules = $T_1$

Molecules helium gas = x

Moles of helium has = $n_1= \frac{x}{N_A}$

PV = nRT (Ideal gas equation)

$PV=n_1RT_1$ ...[1]

After removal of helium gas only a fourth of the gas molecules remains and pressure in the container and volume should remain same.

Molecules of helium left after removal = $\frac{x}{4}$

Moles of helium has left after removal = $n_2= \frac{x}{4\times N_A}$

$PV=n_2RT_2$ ...[2]

$n_1RT_1=n_2RT_2$

$\frac{x}{N_A}\times T_1=\frac{x}{4\times N_A}\times T_2$

$T_1=\frac{T_2}{4}$

$T_2=4T_1$

The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.

6 0

3 years ago

In the simulation, open the micro mode, then select solutions indicated below from the dropdown above the beaker in the simulati

Rzqust [24]

Milk (lowest acidity) < Coffee < Orange juice < Soda pops < vomit < Battery acid (highest acidity)

explanation :

pH values of all :

battery acid pH = 1.0

vomit pH = 2.0

soda pop pH = 2.5

orange juice pH = 3.5

coffee pH = 5.0

milik pH = 6.5

pH value is lesser acidity is more . high pH indicate lesser acidic nature

3 0

2 years ago

2. Which of the following expressions is generally used for solubility? (1 point)

miskamm [114]

Answer:

For 2: The correct answer is grams of solute per 100 grams of solvent.

For 3: The correct answer is supersaturated.

For 4: the correct answer is the solubility decreases.

Explanation:

For 2:

Solubility is defined as the property which refers to the ability of the solute that can be dissolved in a solvent. It is defined as the number of grams of solute per 100 grams of solvent.

For 3:

Unsaturated solution is defined as the solution in which amount of solute that is dissolved in the solvent is less.

Saturated solution is defined as the solution in which no more solute can be dissolved in the given amount of solvent.

Emulsion is defined as the dispersion of one liquid in another liquid in which it is not soluble.

Supersaturated solution is defined as the solution in which solvent contains more amount of solute than the required amount. These solutions help in the process of crystallization.

When a crystal is added to a supersaturated solution, more and more particles come out of the solution and this process is known as crystallization.

For 4:

According to the Henry's Law

The solubility of the gas in a liquid is directly proportional to the partial pressure of the gas.

$\text{Solubility of a gas in a liquid}\propto \text{Partial pressure of the gas}$

With increase in the partial pressure, the solubility of the gas in liquid also increases and vice-versa.

Hence, the correct answer is the solubility decreases.

7 0

3 years ago

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Which two layers are part of the thermosphere?

borishaifa [10]

Answer:

exosphere and ionosphere.

Explanation:

very high up,the earth's atmosphere becomes very thin. the region where atoms and moleculesescape into space is referred to as the exosphere. exosphere is on top of the thermosphere.

scientists what is called the ionospherean extension of the thermosphere. so technically, ionosphere is not another atmospheric layer.

6 0

3 years ago

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