One mole of particles of any substance contains how many particles?

Lithium has two stable isotopes with masses of 6.01512 amu and 7.01600 amu. The average molar mass of Li is 6.941 amu. What is t

Dvinal [7]

Answer : The percent abundance of Li isotope-1 and Li isotope-2 is, 6.94 % and 93.1 % respectively.

Explanation :

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

Let the fractional abundance of Li isotope-1 be 'x' and the fractional abundance of Li isotope-2 will be '100-x'

For Li isotope-1 :

Mass of Li isotope-1 = 6.01512 amu

Fractional abundance of Li isotope-1 = x

For Li isotope-2 :

Mass of Li isotope-2 = 7.01600 amu

Fractional abundance of Li isotope-2 = 100-x

Average atomic mass of Li = 6.941 amu

Putting values in equation 1, we get:

$6.941=[(6.01512\times x)+(7.01600\times (100-x))]$

By solving the term 'x', we get:

$x=694.048$

Percent abundance of Li isotope-1 = $\frac{694.048}{100}=6.94\%$

Percent abundance of Li isotope-2 = 100 - x = 100-6.94 = 93.1 %

6 0

2 years ago

Use the drop-down menus to classify each of the following as an addition, substitution, elimination, or

OLga [1]

Answer:

CH3CHO+H2O → CH3OCH3 - addition

CH,CICH CI + Zn → C2H4 + ZnCl2 - elimination

CH3CH3Br + OH – CH3CH3OH + Br - substitution

2CH2COOH >>(CH3CO)20 + H20 - condensation

Explanation:

An addition reaction is a reaction in which a specie is added across the double bond as we can see in CH3CHO+H2O → CH3OCH3.

In an elimination reaction, a small molecule is lost from a saturated compound to form the corresponding unsaturated compound as in CH,CICH CI + Zn → C2H4 + ZnCl2

In a substitution reaction, a chemical moiety replaces another in a molecule as in; CH3CH3Br + OH – CH3CH3OH + Br .

A condensation reaction is in which two molecules are joined together to form a bigger molecule as in; 2CH2COOH >>(CH3CO)20 + H20.

4 0

3 years ago

An atom of calcium contains 20 protons how many electrons does it have

harina [27]

20.

Atomic number is equivalent to its protons and electrons. :)

4 0

3 years ago

Which of the following factors could you change in a system and not change its induced EMF?

krok68 [10]

The options attached to the question above are listed below:
A. Magnetic field.
B. Type of wire.
C. Velocity of the wire.
D. Length of the wire in the field.

ANSWER
The correct option is B.
The factors that determine the induced current in a system are: the number of wires in the coil, the strength of the magnetic field and speed of armature rotation [speed of cutting]. Generally, the induced electromotive force across a conductor is equal to the rate at which magnetic flux is cut by the conductor. The type of wire used does not affect the induced EMF.

8 0

3 years ago

Read 2 more answers

I can be found in the 4th period on the periodic table.

Rainbow [258]

Vanadium (V)

Vanadium is the only one in the 4th period here so

4 0

3 years ago