Isotopes and Isotones

Q.

Argon atoms have a mass number of 40, but a relative atomic mass of 39.948 why is this so?

Q. The atomic number of sulphur is 16 and its atomic mass is 32. What is the number of neutrons in sulphur?

1. 8
2. 16
3. 18
4. 32

Q.

Is everything in the whole universe made up of atoms. If not what can be the examples given for such substance?

Q.

Can atom exist independently

Q. The elements hydrogen, oxygen, carbon and nitrogen are called as _________.

1. alkali metal
2. organogens
3. isotopes
4. halogens

Q.

The binding energy of a nucleus is a measure of its

Q. Can the molecules of water be seen through a microscope?

Q.

Find the ratio by mass of the combining elements in ${\mathrm{MgCl}}_2$

Q. How did the discovery of isotopes contradict Dalton's atomic theory?

Q. A naturally occuring sample of copper consists of 69.2% of ${}^{63}Cu$ and 30.8% of ${}^{65}Cu$. The relative mass of ${}^{63}Cu$ is 62.93 and that of ${}^{65}Cu$ is 64.93. Find the atomic mass of a naturally occuring sample of copper.

1. 64.348
2. 63.546
3. 64.12
4. none of these
   

Q.

(a) Where is the nucleus of an atom situated ?

(b) What are orbits or shells of an atom ?

(c)What are isotopes ? How does the existence of isotopes contradict Dalton's atomic theory ?

Q.

Define noble gases

Q. a. What are Isotopes?
b. Write any three applications of Avogadros law?

Q.

The neutron number of Sodium is equal to the neutron number of Magnesium. What do you call this characteristic as?

1. Isocore

2. Isotone

3. Isotope

4. None of the choices

Q.

‘The number of neutrons in an atom is always equal to or higher than the number of protons present. Verify the statement.

Q. What will be the ratio of $C{l}^{35}$ and $C{l}^{37}$ respectively in chlorine if the average atomic mass of chlorine is 35.5?

1. 1 : 1
2. 3 : 1
3. 2 : 1
4. 3 : 2

Q. Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes?

Q.

How does isotope contradict Dalton theory?

Q. Argon has three isotopes with relative atomic masses of $36,38$ and $40$. Given that the average relative atomic mass of naturally occurring argon is $39.95$. Which of the following statements must be correct?

1. ${}^{40}Ar$ is less abundant than ${}^{38}Ar$
2. ${}^{40}Ar$ is more abundant than either ${}^{36}Ar$ or ${}^{38}Ar$.
3. ${}^{36}Ar$ is more abundant than ${}^{40}Ar$
4. ${}^{40}Ar{,}^{38}Ar$ and ${}^{36}Ar$ are equally abundant

Q. Lightest isotope in the periodic table is:

1. deuterium
2. tritium
3. protium
4. none of these

Q.

A chemical element which has the shortest name forms maximum number of isotopes.Identify the element, state its symbol and draw the structure of atom.

Q. The number of water molecules differing in molecular mass formed by hydrogen isotopes and ${}^{1}H,{}^{2}H,{}^{3}H$ and oxygen isotopes ${}^{16}O,{}^{17}O,{}^{18}O$ is _________________.

1. $6$
2. $9$
3. $12$
4. $18$

Q. Boron has two isotopes B - 10 and B - 11. If the average atomic mass of boron is 10.80 u. What is the percentage of a heavier isotope?

1. 30
2. 70
3. 20
4. 80

Q.

Radioactive substances are only harmful and have no useful applications.

1. True

2. False

Q.

What do you mean by isotopes and isobars?mention important uses of radio isotopes

Q. Statement I: ${}^{20}Ne$ and ${}^{22}Ne$ are isotopes.

Statement II: Noble gases do not exist as isotopes as they are inert.

1. Both statements are incorrect
2. Statement I is correct but statement II is incorrect
3. Statement I is incorrect but statement II is correct
4. Both statements are correct

Q. Atomic mass of an element is not a whole number because:

1. it contains electrons, protons and neutrons
2. it contains isotopes
3. it contains allotropes
4. all of the above

Q. Chlorine exists in two isotopic forms, $Cl-37$ and $Cl-35$ but its atomic mass is $35.5$. This indicates the ratio of $Cl-37$ and $Cl-35$ is approximately:

1. $1:2$
2. $1:1$
3. $1:3$
4. $3:1$

Q.

Atom are made up of (a) _________ , (b)____________and (c)___________.

Q.

1. True
2. False