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3 years ago

Plz help need this ASAP

Chemistry

1 answer:

Feliz [49]3 years ago

4 0

Explanation:

option no 4 is correct answer

I hope is helpful

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neon has 3 different isotopes, neon-20, neon-21, and neon-22. the first isotope has a mass 19.992 amu and an abundance of 90.60%

il63 [147K]

Isotopes

Mass atom of Neon: 20.1797 amu

Mass atom X = mass isotope 1 . % + mass isotope 2.% +.....

$\tt 20.1797=19.992\times 0.906+x\times 0.0021+21.991.0\times 0920\\\\x=20.846~amu$

4 0

3 years ago

How many atoms (mol) is in 10g of sodium, sodium chloride and Iron chloride?

SashulF [63]

Answer:

See explanation

Explanation:

Molar mass of NaCl = 58.5 g

Number of moles contained in 10 g of NaCl = 10 g/58.5 g = 0.17 moles

If 1 mole of NaCl contains 6.02 * 10^23 atoms

0.17 moles of NaCl contains 0.17 * 6.02 * 10^23 atoms = 1.02 * 10^23 atoms

Molar mass of Fe II chloride = 126.751 g/mol

Number of moles = 10 g/126.751 g/mol = 0.0789 moles

Number of atoms = 0.0789 moles * 6.02 * 10^23 atoms = 4.7 * 10^22 atoms

Molar mass of Na = 23 g/mol

Number of moles = 10g/23 g/mol = 0.43 moles

Number of atoms = 0.43 moles * 6.02 * 10^23 atoms = 2.59 * 10^ 23 atoms

8 0

3 years ago

True or false: the part of photosynthesis that does not require light is the Calvin cycle

Mumz [18]

False False False False

5 0

4 years ago

Read 2 more answers

If element X has 49 protons, how many electrons does it have? Your Answer:

finlep [7]

It has 49 electrons as well. The amount of protons and electrons are equal.

8 0

4 years ago

Suppose you measure the absorbance of a yellow dye solution in a 1.00 cm cuvette. The absorbance of the solution at 427 nm is 0.

Dimas [21]

Answer:

The concentration of the solution, $C=7.2992\times 10^{-6} M$

Explanation:

The absorbance of a solution can be calculated by Beer-Lambert's law as:

$A=\varepsilon Cl$

Where,

A is the absorbance of the solution

ɛ is the molar absorption coefficient ( $L.mol^{-1}.cm^{-1}$ )

C is the concentration ( $mol^{-1}.L^{-1}$ )

l is the path length of the cell in which sample is taken (cm)

Given,

A = 0.20

ɛ = 27400 $M^{-1}.cm^{-1}$

l = 1 cm

Applying in the above formula for the calculation of concentration as:

$A=\varepsilon Cl$

$0.20= 27400\times C\times 1$

$C = \frac{0.20}{27400\times 1} M$

So , concentration is:

$C=7.2992\times 10^{-6} M$

4 0

3 years ago