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3 years ago

How manhhy neutrons does element x have if its atomic number is 24 and its mass number is 77??

Chemistry

1 answer:

nadezda [96]3 years ago

5 0

77(no of protons and neutrons)-24(no of protons)
53 nuetrons

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Latex, DNA, and cellulose are all examples of Question 11 options: A) natural polymers. B) natural monomers. C) monomers. D) syn

RoseWind [281]

Answer:

A) natural polymers

Explanation:

pls mark as brainliest

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3 years ago

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A binary compound created by reaction of nitrogen and an unknown element E contains 30.46% N and 69.54% E by mass. If the formul

aleksklad [387]

Answer:

15.95

Explanation:

This question is a modification of the calculation of the empirical formula of a compound given its percent composition and atomic weights of the elements in the compound.

Here we are given the formula and the percent composition, so we know that there are 4 atoms of E per 2 atoms of N so lets solve using the information given.

In 100 grams of the binary compound we have

30.46 g N

69.54 g E

The number of moles is the mass divided by atomic weight:

mol N = 30.46 g / A.W N = 30.46 g / 14.00 g/mol = 2.18 mol N

mol E = 65.54 g / A.W E

Thus,

4 mol E/ 2 mol N = ( 69.54 g/ A.W E ) / 2.18

2 A.E = 65.54 g / 2.18 ⇒ A.W E = 69.54 g / ( 2 x 2.18 ) = 15.94 g

So the A.W is 15.94 g/mol which is close the atomic weight of O.

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3 years ago

Identify one trait in a plant that could be changed with selective breeding and explain how the change would be useful? Science.

saul85 [17]

The answers is 67 don’t ask me I don’t know but trying to get free points

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3 years ago

Sulfur trioxide, so3, is made industrially in enormous quantities by combining oxygen and sulfur dioxide, so2. what amount (mole

DedPeter [7]

The answer is 37.5 moles

The explanation:

1- when we have the mass of SO3 in Kg so, first we have to convert it to grams:

mass = 3 * 1000 = 3000 g

2- we need to get the molar mass of SO3 :

molar mass of SO3 = 32 + (16*3)

= 80 g/mol

3- then we can use this formula to get number of moles:

moles = mass / molar mass

= 3000 g / 80 g/mol

= 37.5 moles

6 0

3 years ago

A 3.31-g sample of lead nitrate, Pb(NO3)2, molar mass = 331 g/mol, is heated in an evacuated cylinder with a volume of 2.53 L. T

Dahasolnce [82]

Answer:

0.486atm is the pressure of the cylinder

Explanation:

1 mole of Pb(NO₃)₂ descomposes in 4 moles of NO2 and 1 mole of O2. That is 1 mole descomposes in 5 moles of gas.

To find the pressure of the cylinder, we need to find moles of gas produced, and using general gas law we can determine the pressure of the gas:

Moles Pb(NO₃)₂ and moles of gas:

3.31g * (1mol / 331g) = 0.01 moles of Pb(NO₃)₂.

That means moles of gas produced is 0.05 moles.

Pressure of the gas:

Using PV = nRT

P = nRT/V

Where P is pressure (Incognite)

V is volume (2.53L)

R is gas constant (0.082atmL/molK)

T is absolute temperature (300K)

And n are moles of gas (0.05 moles)

P = 0.05mol*0.082atmL/molK*300K / 2.53L

P = 0.486atm is the pressure of the cylinder

3 0

3 years ago