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4 years ago

What relationship exists between the mass number of an element and the isotopes of that element?

Chemistry

2 answers:

labwork [276]4 years ago

8 0

The mass number plays an important role for elements and their isotopes. Mass number comes from the addition of protons and neutrons (their weight). Isotopes are the elements, but with a different number of neutrons. So in turn, by subtracting the number of protons (atomic number) from the mass, you can find the number of neutrons.

Sergio039 [100]4 years ago

4 0

Find the attached document.

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Calculate the following quantity: molarity of a solution prepared by diluting 45.45 mL of 0.0404 M ammonium sulfate to 550.00 mL

dybincka [34]

Answer:

$M_2=3.34x10^{-3}M$

Explanation:

Hello!

In this case, since a dilution process implies that the moles of the solute remain the same before and after the addition of diluting water, we can write:

$M_1V_1=M_2V_2$

Thus, since we know the volume and concentration of the initial sample, we compute the resulting concentration as shown below:

$M_2=\frac{M_2V_2}{V_1} =\frac{45.45mL*0.0404M}{550.00mL}\\\\M_2=3.34x10^{-3}M$

Best regards!

5 0

3 years ago

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? Hint: The pKa of phosphate is 6.86.

AlekseyPX

Answer:

The pH value of the mixture will be 7.00

Explanation:

Mono and disodium hydrogen phosphate mixture act as a buffer to maintain pH value around 7. Henderson–Hasselbalch equation is used to determine the pH value of a buffer mixture, which is mathematically expressed as,

$pH=pK_{a} + log(\frac{[Base]}{[Acid]})$

According to the given conditions, the equation will become as follow

$pH=pK_{a} + log(\frac{[Na_{2}HPO_{4} ]}{[NaH_{2}PO_{4}]})$

The base and acid are assigned by observing the pKa values of both the compounds; smaller value means more acidic. NaH₂PO₄ has a pKa value of 6.86, while Na₂HPO₄ has a pKa value of 12.32 (not given, but it's a constant). Another more easy way is to the count the acidic hydrogen in the molecular formula; the compound with more acidic hydrogens will be assigned acidic and vice versa.

Placing all the given data we obtain,

$pH=6.86 + log(\frac{0.058}{0.042})$

$pH=7.00$

5 0

4 years ago

Why is not used at nuclear plant as a soverce for electrical energy

nikitadnepr [17]

The biggest reason is radioactive wastes. Nuclear power generated radioactive wastes like Uranimum, plutonium and amercium that inhibits gene expression and causes cancer to the environment. Nuclear plants use to release these wastes into the oceans, and it causes fishes to exhibit gender change, 3 eyes, 2 tails etc. The impact on human shows signs of serious blood, liver and lung cancers.

There are currently no way to get rid of these wastes as they take hundred thousands of years to decompose.

Another reason is they cause a small amount of green gas emission. Releases CO2 to the sky. They exhibit radioactive gas emission as well (causes cancer) .

7 0

3 years ago

CAN SOMEONE HELP ME!!!

NISA [10]

Answer:

I think D

Explanation:

4 0

3 years ago

Read 2 more answers

Calculate the [OH-]<br> [H+]=0.000025

Harman [31]

Explanation:

There are several ways to define acids and bases, but pH and pOH refer to hydrogen ion concentration and hydroxide ion concentration, respectively. The "p" in pH and pOH stands for "negative logarithm of" and is used to make it easier to work with extremely large or small values. pH and pOH are only meaningful when applied to aqueous (water-based) solutions. When water dissociates it yields a hydrogen ion and a hydroxide.

3 0

3 years ago