Your answer is B and the element is Carbon
So what your looking for is matching isotopes. Isotopes are elements that are the same in amount of protons but different in mass meaning different number in neutrons. Because when you add the total protons and neutrons together you get your atomic mass. So this can be written as X=said element, top number above=different atomic mass, bottom number below=atomic number. Hope this help!!
Be careful because answer A has same masses but different atomic numbers so different atoms(elements)!!!
☃️ Chemical formulae ➝ 
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<u>How to find?</u></h3>
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
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<u>Solution:</u></h3>
Atomic weight of elements:
Ca = 40
C = 12
O = 16
❍ Molecular weight of
= 40 + 12 + 3 × 16
= 52 + 48
= 100 g/mol
❍ Given weight: 10 g
Then, no. of moles,
⇛ No. of moles = 10 g / 100 g mol‐¹
⇛ No. of moles = 0.1 moles
☄ No. of moles of Calcium carbonate in that substance = <u>0.1 moles</u>
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Paper chromatography can be applied to "ink" to determine if it is a pure substance or a "mixture" of pure substances (in which two or more pure substances are combined). Since, tested with paper chromatography, "ink" separates into its constituent pure substances, Ink is a mixture.
I hope this helps.
P.S. Thank you for choosing me as brainliest answer on my last.
Can you be more specific about what we are supposed to write
Answer:
1,869.97 grams of Be(NO3)2
Explanation:
Be(NO3)2 = Be N2 O6
Be=9.012182g/mole
N2=28.0134g/mole
O6=96g/mole
therefore Be(NO3)2 gives you 187.56g in one mole
so 9.97 moles means there is 9.97 times more
9.97mole Be(NO3)2 * 187.56g Be(NO3)2/1mole Be(NO3)2 = 1,869.97g of Be(NO3)2
