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3 years ago

If the atomic number of an element is 6 and its mass number is 15, how many neutrons are in the atom's nucleus?

2 answers:

6 0

Atomic Number is the same as the number of protons in an element.
Mass Number is the number of Protons + Neutrons in an element.

Atomic Number: 6 means 6 Protons
Mass Number: 15 means 15 atoms that are a proton/neutron.
We are given out of the 15 atoms, 6 of them are protons, so the other 9 must be Neutrons.

15 - 6 = 9 so there must be 9 Neutrons.

There are 9 Neutrons in atom's nucleus.

Give Brainiest if you think this is the best answer and explanation. Thanks!

melisa1 [442]3 years ago

5 0

¹⁵₆X
- 6 protons
- 6 electrons
- 15-6 = 9 neutrons

:)

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Phosphorus oxychloride has the chemical formula POCl3, with P as the central atom. In order to minimize formal charge, how many

Elina [12.6K]

Answer:

Phosphorus makes 5 bonds with other atoms

Explanation:

$POCl_{3}$ has total 32 number of valence electrons (P has 5 , O has 6 and Cl has 7 valence electrons).

These valence electrons are used to draw Lewis structure of $POCl_{3}$ .

Formal charge on an atom = (no. of valence electrons of the atom)-(no. of covalent bonds attached to the atom)-(no. of electrons in lone pair of the atom)

Applying octet rule (atoms have eight electrons in their valence shell) and minimizing formal charge of $POCl_{3}$ , it has been found that P makes total 5 bonds with rest of the atoms.

Lewis structure of $POCl_{3}$ along with formal charge (in parentheses) has been given below.

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2 years ago

1. A chemist prepares hydrogen fluoride by means of the following reaction:

Natasha_Volkova [10]

Answer:

a) Theoretical Yield of HF = 5.64 grams

b) Percentage Yield = 39%

Explanation:

Reaction Given:

CaF2 + H2SO4 -> CaSO4 + 2HF

CaF2 = 11g

H2SO4 = Used in excess

HF = 2.2 g production = Actual Yield

So, Let's write down the molar masses:

Molar Mass of CaF2 = 78 g /mol

Molar Mass of HF = 20 g/mol

From the reaction, we can see the 1 mole of CaF2 gives the 2 moles of HF

i.e

a) Theoretical Yield of HF:

1 mole CaF2 = 2 moles HF

78 g CaF2 = 2 x 20 g of HF

78 g CaF2 = 40 g of HF

1 g CaF2 = 40g/78g of HF

And in the question it is given that chemist used 11 g of CaF2 so,

1 x 11 g of CaF2 = 11 x 40/78 g of HF

11 g of CaF2 = 440/78 g of HF

11 g of CaF2 = 5.64 g of HF

And this is the theoretical yield

Theoretical Yield of HF = 5.64 grams

b) Now, calculate the Percentage Yield of HF

Percentage Yield = Actual Yield /Theoretical Yield x 100

Percentage Yield = 2.2 g /5.64 g x 100

Percentage Yield = 39%

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2 years ago

What is the balanced equation for Al+Fe3N2>AlN+Fr?

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Answer:

2 AL + Fe3N2 = 2 ALN + 3 Fe

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3 years ago

PLEASE ANSWERRRRR: A by-product of both fission and fusion is: Question 1 options: Beta particle Alpha Particle Energy Proton

9966 [12]

A by-product of both fission and fusion is Energy.

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So fission and fusion both released large amount of energy.

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3 years ago

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C. Because both reactants and products continue to form.

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