All atoms of a given element are identical was proven wrong because of the existence or

What is the element with 2 protons on the

Paul [167]

Answer:

Helium

Explanation:

7 0

2 years ago

What differentiates one element from another

worty [1.4K]

I think the number of protons in the nucleus the number of valence electrons atomic mass...

8 0

2 years ago

Can you guys give some science fair project ideas(8th grade)

Anton [14]

Answer
i’m in 7th grade but for this years science fair i did, “ how does temperature affect the elasticity of rubber bands”

Guide a growing plant through a maze.
8th Grade Science Plant Maze KiwiCo

Prove that plants really do seek out the light by setting up a simple or complex maze. This is a simple 8th grade science project with really cool results.

Blow out a candle with a balloon.

Blowing up a balloon with baking soda and vinegar is the classic acids and bases experiment. Take it a step further by experimenting with the carbon dioxide it produces. (Don’t be afraid of fire in the science

Stand on a pile of paper cups.

Combine physics and engineering and challenge 8th grade science students to create a paper cup structure that can support their weight. This is a cool project for aspiring architects.

hope this helps and have a wonderful day :)

5 0

2 years ago

Antimony has two naturally occuring isotopes, 121 Sb and 123 Sb . 121 Sb has an atomic mass of 120.9038 u , and 123 Sb has an at

valina [46]

Answer:

Percentage abundance of 121 Sb is = 57.2 %

Percentage abundance of 123 Sb is = 42.8 %

Explanation:

The formula for the calculation of the average atomic mass is:

$Average\ atomic\ mass=(\frac {\%\ of\ the\ first\ isotope}{100}\times {Mass\ of\ the\ first\ isotope})+(\frac {\%\ of\ the\ second\ isotope}{100}\times {Mass\ of\ the\ second\ isotope})$

Given that:

Since the element has only 2 isotopes, so the let the percentage of first be x and the second is 100 -x.

For first isotope, 121 Sb :

% = x %

Mass = 120.9038 u

For second isotope, 123 Sb:

% = 100 - x

Mass = 122.9042 u

Given, Average Mass = 121.7601 u

Thus,

$121.7601=\frac{x}{100}\times 120.9038+\frac{100-x}{100}\times 122.9042$

$120.9038x+122.9042\left(100-x\right)=12176.01$

Solving for x, we get that:

x = 57.2 %

<u>Thus, percentage abundance of 121 Sb is = 57.2 % </u>

<u>percentage abundance of 123 Sb is = 100 - 57.2 % = 42.8 %</u>

6 0

3 years ago

If the molecular weight of a semiconductor is 27.9 grams/mole and the diamond lattice constant is 0.503 nm, what is the density

adelina 88 [10]

Explanation:

The given data is as follows.

Mass = 27.9 g/mol

As we know that according to Avogadro's number there are $6.023 \times 10^{26}$ atom present in 1 mole. Therefore, weight of 1 atom will be as follows.