The numbers of protons in a neutral atom will be equal to the number of-

Iodine is 80% 127I, 17% 126I, and 3% 128I. Calculate the average atomic mass of Iodine.

trasher [3.6K]

<h3>The average atomic mass of Iodine : 126.86 amu</h3><h3>Further explanation</h3>

Given

80% 127I, 17% 126I, and 3% 128I.

Required

The average atomic mass

Solution

The elements in nature have several types of isotopes

Atomic mass is the average atomic mass of all its isotopes

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

Atomic mass of Iodine = 0.8 x 127 + 0.17 x 126 + 0.03 x 128

Atomic mass of Iodine = 101.6 + 21.42 + 3.84

Atomic mass of Iodine = 126.86 amu

6 0

3 years ago

Please help !!

Strike441 [17]

1) boiling points increase as molecular weight increase and vice versa. This is due to the increase in van der waals forces between molecules.
2) branching decreases the melting and boiling i.e increase in branching decrease boiling point and melting point. This is due to the fact that there are less point of contact between neighbouring molecules, so molecules are farther apart from each other, which means weaker van der waals(London forces) less energy is required to overcome these force of attraction.
3) In homolytic fission each of the fragment retain one of the bonded electron and radicals are made if the molecule is neutral. In heterolytic fission one fragment gets both bonding electron.
The energy for the heterolytic fission is higher because energy is not only needed to break the covalent bond but also to overcome the force of attraction between oppositely charged ions formed.

7 0

3 years ago

"To determine the amount of heroin in the mixture, you dissolve 1.00 g of the white powdery mixture in water in a 100.0-mL volum

UkoKoshka [18]

Explanation:

Formula to calculate osmotic pressure is as follows.

Osmotic pressure = concentration × gas constant × temperature( in K)

Temperature = $25^{o} C$

= (25 + 273) K

= 298.15 K

Osmotic pressure = 531 mm Hg or 0.698 atm (as 1 mm Hg = 0.00131)

Putting the given values into the above formula as follows.

0.698 = $C \times 0.082 \times 298.15 K
$

C = 0.0285

This also means that,

$\frac{\text{moles}}{\text{volume (in L)}}$ = 0.0285

So, moles = 0.0285 × volume (in L)

= 0.0285 × 0.100

= $2.85 \times 10^{-3
}$

Now, let us assume that mass of $C_{12}H_{23}O_{5}N$ = x grams

And, mass of $C_{12}H{22}O_{11}$ = (1.00 - x)

So, moles of $C_{12}H_{23}O_{5}N = \frac{mass}{\text{molar mass}}$

= $\frac{x}{369}$

Now, moles of $C_{12}H_{22}O_{11} = \frac{(1.00 - x)}{342}$

= $\frac{x}{369} + \frac{(1.00 - x)}{342}$

= $2.85 \times 10^{-3}$

= x = 0.346

Therefore, we can conclude that amount of $C_{12}H_{23}O_{5}N$ present is 0.346 g and amount of $C_{12}H_{22}O_{11}$ present is (1 - 0.346) g = 0.654 g.

4 0

3 years ago

Place these elements in order of LOWEST electronegativity to HIGHEST.

mrs_skeptik [129]

Answer:

Barium

Molebdenum

Cobalt

Nitrogen

Explanation:

science

8 0

3 years ago

Read 2 more answers

Write formulas for binary ionic compounds formed from each of the following pairs of elements

MakcuM [25]

Answer:

Binary compounds of potassium and sulfur:

K₂S

Binary compounds of silver chlorine:

AgCl

Binary compounds of calcium and oxygen:

CaO

Binary compounds of aluminium and iodine:

AlI₃

Binary compounds of barium and nitrogen:

Ba₃ N₂

Binary compounds of sodium and selenium:

Na₂Se

Explanation:

Binary compounds:

The compounds which are made up of the atoms of only two elements are called binary compounds.

For example:

The following compounds are binary:

HCl

H₂O

NH₃

HCl is binary because it is composed of only hydrogen and chlorine. Ammonia is also binary compound because it is made up of only two elements nitrogen and hydrogen.

water is also binary because it is also made up of only two elements hydrogen and oxygen.

Binary compounds of potassium and sulfur:

K₂S

The oxidation state of potassium is +1 and sulfur is -2 so two atoms of potassium will combine with one atom of sulfur.

Binary compounds of silver chlorine:

AgCl

The oxidation state of silver is +1 and chlorine is -1. Both combine to form silver chloride.

Binary compounds of calcium and oxygen:

CaO

calcium oxide is formed by calcium and oxygen. The oxidation state of calcium is +2 and oxygen is -2.

Binary compounds of aluminium and iodine:

AlI₃

The oxidation state of aluminium is +3 and iodine is -1 so three atoms of iodine will combine with one atom of aluminium.

Binary compounds of barium and nitrogen:

Ba₃ N₂

Barium nitride is formed by barium and nitrogen. The oxidation state of nitrogen is -3 and barium is +2.

Binary compounds of sodium and selenium:

Na₂Se

The oxidation state of selenium is -2 ans sodium is +1 so two atoms of sodium will combine with one atom of selenium.

5 0

3 years ago