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3 years ago

Need help with 22 and 24

Chemistry

2 answers:

Anvisha [2.4K]3 years ago

6 0

Answer:

hey there!, I think get some reference from ramsden chemistry book

choli [55]3 years ago

5 0

Answer:

22:

Formular:

$atomic \: mass = \frac{ \sum(isotopic \: mass \times \%abundance)}{100} \\$

substitute:

$atomic \: mass = \frac{(23.985 \times 78.70) + (24.986 \times 10.13) + (25.983 \times 11.17)}{100} \\ \\ = \frac{(1887.620) + (253.108) + (290.230)}{100} \\ \\ = \frac{2430.958}{100} \\ \\ { \boxed{ \boxed{average \: atomic \: mass = 24.3 \: amu}}}$

23:

Same element is represented by same number of protons. 

Answer:

6 protons. 6 protons

7 neutrons. 8 neutrons

6 electrons. 6 electrons

Note: Atoms with same proton number but different mass number are called isotopes

You might be interested in

The radioactive substance cesium-137 has a half-life of 30 years. The amount At (in grams) of a sample of cesium-137 remaining a

stealth61 [152]

Answer: The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g

Explanation:

We are given a function that calculates the amount of sample remaining after 't' years, which is:

$A_t(t)=458\times (\frac{1}{2})^{\frac{t}{30}$

For t = 20 years

Putting values in above equation:

$A_t(t)=458\times (\frac{1}{2})^{\frac{20}{30}$

$A_t(t)=288.522g$

Hence, the amount of sample left after 20 years is 288.522 g

For t = 50 years

Putting values in above equation:

$A_t(t)=458\times (\frac{1}{2})^{\frac{50}{30}$

$A_t(t)=144.26g$

Hence, the amount of sample left after 50 years is 144.26 g

6 0

4 years ago

The reaction of an acid and a base will always produce what kind of salt?

Illusion [34]

Answer:

the answer of the question is c

7 0

2 years ago

If you start with 64g of a radioactive element how many half-lives would occur before 8g remain?

Nonamiya [84]

Answer:

3 half-lives

Explanation:

The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.

Let's suppose we start with 64 g of the radioactive element.

After 1 half-life, the mass of the element will be 32 g.

After 2 half-lives, the mass of the element will be 16 g.

After 3 half-lives, the mass of the element will be 8 g.

3 0

3 years ago

Explain why aluminum does not react with potassium nitrate (KNO3) although it reacts with copper nitrate

Ratling [72]

Answer:

Potassium is more reactive than aluminium, so no reaction takes place. But aluminium is more reactive than copper, so it replaces the copper in copper nitrate

<h3>Explanation:</h3>

More reactive metal compound + less reactive metal

-> no reaction

However

Less reactive metal compound + more reactive metal

-> more reactive metal compound + less reactive metal

This is called substitution reaction where the more reactive metal replaces the less reactive metal in the compound.

7 0

3 years ago

Why do electrons enter the 4s orbital before entering the 3D orbital

garri49 [273]

The 3d sublevel is not filled until after the 4s sublevel, because the 3d sublevel has more energy than the 4s sublevel, and less energy than the 4p sublevel. (:

8 0

3 years ago

Need help with 22 and 24​

Need help with 22 and 24