What do you mean by the region or space that an electron revolves the nucleus in an atom?

Write the appropriate symbol for each of the following isotopes: (a) Z 74, A 186; (b) Z 80, A 201; (c) Z 34, A 76; (d) Z 94, A 2

beks73 [17]

Answer: a) $_{74}^{186}\textrm{W}$

b) $_{80}^{201}\textrm{Hg}$

c) $_{34}^{76}\textrm{Se}$

d) $_{94}^{239}\textrm{Pu}$

Explanation:

General representation of an element is given as:_Z^A\textrm{X}

where,

Z represents Atomic number

A represents Mass number

X represents the symbol of an element

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

It is characteristic of a particular element.

Atomic number = Number of electrons = Number of proton

a) Z 74, A 186: $_{74}^{186}\textrm{W}$

b) Z 80, A 201: $_{80}^{201}\textrm{Hg}$

c) Z 34, A 76: $_{34}^{76}\textrm{Se}$

d) Z 94, A 239.: $_{94}^{239}\textrm{Pu}$

6 0

3 years ago

A) What characteristics of physical properties distinguish metals from nonmetals?

salantis [7]

Answer:

The answer to your question is:

Explanation:

a)

Metals: are shiny, malleable and ductile, they can conduct electricity and heat, form cations in aqueous solutions.

Nonmetals: non-lustrous, brittle, not good conductors of heat and electricity, form anions in aqueous solutions.

b)

Metals are located in the left side of the periodic table

Nonmetals are located in the right side of the periodic table.

c)

Metal are use to make pans because they are good conductors of heat and also are malleable and ductile.

Nonmetals are used to make sleeping bags and coolers because they do not conduct heat so they can isolate matter.

6 0

3 years ago

What thype of bond requires the give and take of electrons ?

DedPeter [7]

Ionic bond involves electrostatic attraction between oppositely charged ions.
The ions are atoms that have gained 1 or more electrons and atoms that have lost 1 or more electrons.
Answer: The type of bond that requires the give and take of electrons is Ionic bond

6 0

4 years ago

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Which of the following is an acceptable IUPAC name?(A) 3,6-dimethylheptane (B) 2-ethyl-3-methylheptane (C) 5-methyl-3-ethylhepta

bearhunter [10]

Answer:

D) 4-ethyl-4-methylheptane

Explanation:

The rules for naming of alkanes with substituents.

1. The carbon chain with the maximum number of carbon atoms must be selected as a parent chain.

2.Numbering should be done in such a way that each substituent gets the least number.

3. Substituents whose name comes before the another substituents's name in the English alphabet is written first.

4. Substituents are written first with their location in the chain and the name of the parent chain is done. Numbers are separated from numbers by comma and numbers are separated from letters by using hyphen.

Considering (a) 3,6-dimethylheptane

Violation of Rule - 2 mentioned above

The numbering of the parent chain is not done in a right way. Numbering must be done such that each substituent gets the least number. So, The correct name is 2,5-dimethylheptane

Considering (b) 2-ethyl-3-methylheptane

Violation of Rule - 1 mentioned above.

The carbon chain with the maximum number of carbon atoms must be selected as a parent chain. The parent chain selected is of 7 carbon atoms but the parent chain is of 8 carbon atoms. So, The correct name is 3,4-dimethyloctane

Considering (c) 5-methyl-3-ethylheptane

Violation of Rule - 3 mentioned above.

'e' comes before 'm' . So, ethyl- is written first than methyl- . So, The correct name is 3,6-dimethyloctane

Considering (d) 4-ethyl-4-methylheptane

This is a IUPAC name and following all the rules mentioned above.

3 0

3 years ago

List down two applications of isotopes

Sidana [21]

Answer:

Give any two application for isotopes

Isotopes of iodine are used for radiotherapy in treatment of hyperthyroidism, cancer, etc.

Uranium, Radium, Polonium isotopes are used in atomic reactors.

Cobalt isotopes are used for irradiation of food products.

5 0

3 years ago

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