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3 years ago

How can two atoms of the same chemical element be different?

1 answer:

8 0

The answer is B as isotopes are different versions of the same chemical element containing the same amount of protons and electrons but different amounts of neutrons.

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What is the mass, in amu, of an atom with one proton and two neutrons?

Neko [114]

mass of proton mp=1.672621898e-27 kg and 1 amu=1.66053904e-27kg so it’s just divition (1.672621898e-27 / 1.66053904e-27) =1.007276 amu

4 0

3 years ago

If the pH is 10, what is the concentration of hydroxide ion?

AleksandrR [38]

Answer : The correct option is, $10^{-4}M$

Explanation : Given,

pH = 10

First we have to calculate the pOH.

$pH+pOH=14\\\\pOH=14-pH\\\\pOH=14-10=4$

Now we have to calculate the $OH^-$ concentration.

$pOH=-\log [OH^-]$

$4=-\log [OH^-]$

$[OH^-]=1.0\times 10^{-4}M$

Therefore, the $OH^-$ concentration is, $1.0\times 10^{-4}M$

7 0

3 years ago

Air containing 20.0 mol% water vapor at an initial pressure of 1 atm absolute is cooled in a 1- liter sealed vessel from 200°C t

chubhunter [2.5K]

Answer:

This solution is quite lengthy

Total system = nRT

n was solved to be 0.02575

nH20 = 0.2x0.02575

= 0.00515

Nair = 0.0206

PH20 = 0.19999

Pair = 1-0.19999

= 0.80001

At 15⁰c

Pair = 0.4786atm

I used antoine's equation to get pressure

The pressure = 0.50

2. Moles of water vapor = 0.0007084

Moles of condensed water = 0.0044416

Grams of condensed water = 0.07994

Please refer to attachment. All solution is in there.

6 0

3 years ago

Massive amounts of energy are contained in an atom's: Select one:

melamori03 [73]

Nucleus.
____________

6 0

4 years ago

Two unknown molecular compounds were being studied. A solution containing 5.00 g of compound A in 100. g of water froze at a low

LenaWriter [7]

Answer:

Compound B has greater molar mass.

Explanation:

The depression in freezing point is given by ;

$\Delta T_f=i\times k_f\times m$ ..[1]

$m=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Mass of solvent in kg}}$

Where:

i = van't Hoff factor

$k_f$ = Molal depression constant

m = molality of the solution

According to question , solution with 5.00 g of A in 100.0 grams of water froze at at lower temperature than solution with 5.00 g of B in 100.0 grams of water.

The depression in freezing point of solution with A solute: $\Delta T_{f,A}$