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All questions of Atomic Number and Isotopes for EmSAT Achieve Exam
21H and 31H are _______ .- a)isotopes
- b)isobars
- c)isotones
- d)isochores
Correct answer is option 'A'. Can you explain this answer?
21H and 31H are _______ .
a)
isotopes
b)
isobars
c)
isotones
d)
isochores
|
Saikat Iyer answered |
Atoms of the same element having the same atomic numbers but different mass numbers are termed as isotopes.
Which of the following element is used in the treatment of cancer?- a)Uranium
- b)Cobalt
- c)Nickel
- d)Iodine
Correct answer is option 'B'. Can you explain this answer?
Which of the following element is used in the treatment of cancer?
a)
Uranium
b)
Cobalt
c)
Nickel
d)
Iodine
|
Jyoti Kapoor answered |
Elements Used in Radiation Therapy. Radiation therapy is an important cancer treatment along with chemotherapy and surgery. The most famous type is probably gamma ray irradiation by radioactive cobalt-60.
Which of the following elements has 17 electrons and 17 protons?- a)Sodium
- b)Sulphur
- c)Chlorine
- d)Aluminium
Correct answer is option 'C'. Can you explain this answer?
Which of the following elements has 17 electrons and 17 protons?
a)
Sodium
b)
Sulphur
c)
Chlorine
d)
Aluminium
|
Sarita Reddy answered |
Isotopes of chlorine. Chlorine atoms contain 17 protons and 17 electrons. About 75 per cent of chlorine atoms have 18 neutrons, while about 25 per cent have 20 neutrons.
The two isotopes of chlorine are 3517Cl and 3517Cl in the ratio of 3:1. What is the average atomic mass of the chlorine atom?- a)72 u
- b)37 u
- c)35.5 u
- d)35 u
Correct answer is option 'C'. Can you explain this answer?
The two isotopes of chlorine are 3517Cl and 3517Cl in the ratio of 3:1. What is the average atomic mass of the chlorine atom?
a)
72 u
b)
37 u
c)
35.5 u
d)
35 u
|
Pratul Garg answered |
Formula for cocentration is average atomic mass =concentartion of 1isotope multiply by it's atomic mass plus 2 concentration multiply byatomic mass of 2 / 100
Neon occurs as two isotopes of mass numbers 20 and 22. Its relative atomic mass is 20.2. What is the percentage of 20Ne in naturally occurring neon?- a)90
- b)20
- c)80
- d)10
Correct answer is option 'A'. Can you explain this answer?
Neon occurs as two isotopes of mass numbers 20 and 22. Its relative atomic mass is 20.2. What is the percentage of 20Ne in naturally occurring neon?
a)
90
b)
20
c)
80
d)
10
|
C K Academy answered |
Let the relative abundance% of Ne -20 = x1
So, relative abundance% of Ne -22 = x2
So, relative abundance% of Ne -22 = x2
Now, we know that atomic mass = sum of relative abundance in atomic mass of each isotope / 100%
20.2 = 20 x1 + 22 x2 / x1 +x2
20.2 x1 + 20.2x2 = 20x1 + 22x2
0.2x1 = 1.8 x2
20.2 x1 + 20.2x2 = 20x1 + 22x2
0.2x1 = 1.8 x2
x1 / x2 = 1.8/ 0.2 = 9/1 ( relative abundance)
x1% = 9/10 * 100 = 90% lighter isotopes
x2% = 1/ 10* 100 = 10% heavier isotope
x2% = 1/ 10* 100 = 10% heavier isotope
Which one of the following statements is correct about isotopes?- a)Each isotope of an element is a pure substance.
- b)The chemical properties of isotopes are similar.
- c)The physical properties of isotopes are different.
- d)All of above.
Correct answer is option 'D'. Can you explain this answer?
Which one of the following statements is correct about isotopes?
a)
Each isotope of an element is a pure substance.
b)
The chemical properties of isotopes are similar.
c)
The physical properties of isotopes are different.
d)
All of above.
|
Ananya Sharma answered |
Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons. The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number.
An element B has 5 protons and 6 neutrons. What will be the symbol of the element B?- a)116B
- b)11B
- c)115B
- d)511B
Correct answer is option 'C'. Can you explain this answer?
An element B has 5 protons and 6 neutrons. What will be the symbol of the element B?
a)
116B
b)
11B
c)
115B
d)
511B
|
Gagandeep Kaur, 14 9rose answered |
Atomic number of B = number of protons
= number of electron in element
= 5
mass number = number of protons + number of
neutrons
=5+6
=11.
so, c part is correct option.
= number of electron in element
= 5
mass number = number of protons + number of
neutrons
=5+6
=11.
so, c part is correct option.
The atomic number of an element having mass number 23 and number of neutron 12 is ________ .- a)23
- b)11
- c)12
- d)35
Correct answer is option 'B'. Can you explain this answer?
The atomic number of an element having mass number 23 and number of neutron 12 is ________ .
a)
23
b)
11
c)
12
d)
35
|
|
Ananya Sharma answered |
A neutral atom will have the same number of electrons is does protons. Since it has an atomic number of 11 it must have 11 protons. Since it has an atomic mass of 23 it must have 12 neutrons.
The total number of neutrons in 1224Mg2+is:- a)24
- b)12
- c)10
- d)14
Correct answer is option 'B'. Can you explain this answer?
The total number of neutrons in 1224Mg2+is:
a)
24
b)
12
c)
10
d)
14
|
|
Raghavendra Chavan answered |
Neutrons are subatomic particles that have no charge and are found in the nucleus of an atom. They contribute to the mass of the atom but not to its charge. The number of neutrons in an atom can be determined by subtracting the atomic number (number of protons) from the atomic mass (mass number).
In the given question, the element is 1224Mg2. The atomic number of magnesium (Mg) is 12, which means it has 12 protons. The superscript "2" indicates the charge of the magnesium ion, which means it has gained 2 electrons and has an overall charge of +2.
To find the number of neutrons, we need to know the atomic mass of magnesium. The atomic mass of magnesium is approximately 24.31 atomic mass units (amu). However, the given question states that the atomic mass is 1224Mg2, which can be interpreted as 12 + 24 + 2 = 38 amu.
Therefore, the number of neutrons can be calculated as:
Number of neutrons = Atomic mass - Atomic number
= 38 - 12
= 26
Hence, the correct answer is option B) 12 neutrons.
In the given question, the element is 1224Mg2. The atomic number of magnesium (Mg) is 12, which means it has 12 protons. The superscript "2" indicates the charge of the magnesium ion, which means it has gained 2 electrons and has an overall charge of +2.
To find the number of neutrons, we need to know the atomic mass of magnesium. The atomic mass of magnesium is approximately 24.31 atomic mass units (amu). However, the given question states that the atomic mass is 1224Mg2, which can be interpreted as 12 + 24 + 2 = 38 amu.
Therefore, the number of neutrons can be calculated as:
Number of neutrons = Atomic mass - Atomic number
= 38 - 12
= 26
Hence, the correct answer is option B) 12 neutrons.
Why do isotopes have different physical properties?- a)Isotopes of an element have different electronic configuration.
- b)Isotopes have same atomic number.
- c)Isotopes of an element have different mass number.
- d)Isotopes of an element have different atomic number.
Correct answer is option 'C'. Can you explain this answer?
Why do isotopes have different physical properties?
a)
Isotopes of an element have different electronic configuration.
b)
Isotopes have same atomic number.
c)
Isotopes of an element have different mass number.
d)
Isotopes of an element have different atomic number.
|
Surbhi Khanna answered |
Understanding Isotopes
Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. This difference in neutrons leads to variations in their physical properties.
Key Point: Mass Number
- The mass number of an isotope is defined as the total number of protons and neutrons in its nucleus.
- Since isotopes have different numbers of neutrons, they consequently have different mass numbers.
- For example, Carbon-12 (6 protons, 6 neutrons) and Carbon-14 (6 protons, 8 neutrons) are both isotopes of carbon. Their differing mass numbers (12 and 14, respectively) result in different physical properties.
Physical Properties Affected
- Density: Isotopes with higher mass numbers generally have greater density.
- Stability: Some isotopes are radioactive and decay over time, while others are stable. This affects their physical and chemical behavior.
- Boiling and Melting Points: Isotopes can exhibit slight differences in boiling and melting points due to their mass differences.
Conclusion
In summary, the correct answer is option 'C' because isotopes of an element have different mass numbers. This variation in mass leads to distinctions in physical properties, making isotopes unique despite being forms of the same element. Understanding these concepts is essential in fields such as chemistry and nuclear physics.
Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. This difference in neutrons leads to variations in their physical properties.
Key Point: Mass Number
- The mass number of an isotope is defined as the total number of protons and neutrons in its nucleus.
- Since isotopes have different numbers of neutrons, they consequently have different mass numbers.
- For example, Carbon-12 (6 protons, 6 neutrons) and Carbon-14 (6 protons, 8 neutrons) are both isotopes of carbon. Their differing mass numbers (12 and 14, respectively) result in different physical properties.
Physical Properties Affected
- Density: Isotopes with higher mass numbers generally have greater density.
- Stability: Some isotopes are radioactive and decay over time, while others are stable. This affects their physical and chemical behavior.
- Boiling and Melting Points: Isotopes can exhibit slight differences in boiling and melting points due to their mass differences.
Conclusion
In summary, the correct answer is option 'C' because isotopes of an element have different mass numbers. This variation in mass leads to distinctions in physical properties, making isotopes unique despite being forms of the same element. Understanding these concepts is essential in fields such as chemistry and nuclear physics.
The atomic number and the mass number of an element A are 14 and 28 respectively. The number of neutrons are:- a)42
- b)12
- c)28
- d)14
Correct answer is option 'D'. Can you explain this answer?
The atomic number and the mass number of an element A are 14 and 28 respectively. The number of neutrons are:
a)
42
b)
12
c)
28
d)
14
|
Sunidhi Rai answered |
Given,Z=14..... nd A=28.... we know that Z=p... =>p=14........ and A=p+n.... => 28= 14+n.... =>n=28-14.. =>n= 14........ Hence, no of neutrons are 14........
Argon has atomic number of 18 and mass number of 40. Calcium has atomic 20 and mass number 40. Calcium and argon are examples of _______ .- a)isotopes
- b)isobars
- c)isotones
- d)isochores
Correct answer is option 'B'. Can you explain this answer?
Argon has atomic number of 18 and mass number of 40. Calcium has atomic 20 and mass number 40. Calcium and argon are examples of _______ .
a)
isotopes
b)
isobars
c)
isotones
d)
isochores
|
|
Sunidhi Rai answered |
Argon and. Calcium are the example of Isobars...... because Isobars are the elements which have same mass no...ND different atomic no.......
Atomic number is equal to:- a)Number of protons + Number of electrons
- b)Number of protons
- c)Number of protons + Number of neutrons
- d)Number of neutrons
Correct answer is option 'B'. Can you explain this answer?
Atomic number is equal to:
a)
Number of protons + Number of electrons
b)
Number of protons
c)
Number of protons + Number of neutrons
d)
Number of neutrons
|
|
Himaja Ammu answered |
Its equal to no.of protons but mass number =no.of protons +no.of neutrons
An atom is represented by symbol 2314M. What does the number 23 represent?- a)Mass number
- b)Atomic number
- c)Number of protons
- d)Number of neutrons
Correct answer is option 'A'. Can you explain this answer?
An atom is represented by symbol 2314M. What does the number 23 represent?
a)
Mass number
b)
Atomic number
c)
Number of protons
d)
Number of neutrons
|
|
Anita Menon answered |
Nucleons reside inside the nucleus and are denoted by the mass number is denoted as “A.” All atoms of a particular chemical element will have the same atomic number, number of protons present in the nucleus of an atom, but different mass numbers.
The isotopic composition of a certain element X is 80% 24X, 10% 25X and 10% 26X. The relative-atomic mass of X is _______ .- a)24.67
- b)24.25
- c)24.33
- d)24.30
Correct answer is option 'D'. Can you explain this answer?
The isotopic composition of a certain element X is 80% 24X, 10% 25X and 10% 26X. The relative-atomic mass of X is _______ .
a)
24.67
b)
24.25
c)
24.33
d)
24.30
|
|
Arvind Singh answered |
We can use the formula :
Average atomic mass of X =
[(Atomic mass of X1) x (% of X1 )] + [(Atomic mass of X2) x (% of X2 )]
100 100
+ [(Atomic mass of X3) x (% of X3 )]
100
= (24 x 0.8) + (25 x 0.10) + (26 x 0.10)
= 19.2 + 2.5 + 2.6
= 24.3 u
We can use the formula :
Average atomic mass of X = [(Atomic mass of X1) x (% of X1 )] + [(Atomic mass of X2) x (% of X2 )] +
100 100
[(Atomic mass of X3) x (% of X3 )]
100
= (24 x 0.8) + (25 x 0.10) + (26 x 0.10)
= 19.2 + 2.5 + 2.6
= 24.3 u
Which form of iodine is used for the treatment of goiter?- a)An isotone
- b)An isobar
- c)An isochore
- d)An isotope
Correct answer is option 'D'. Can you explain this answer?
Which form of iodine is used for the treatment of goiter?
a)
An isotone
b)
An isobar
c)
An isochore
d)
An isotope
|
|
Aditi Rathore answered |
Isotope is used for the treatment of goiter..
An neutral element A has 3 electrons, the atomic number of an element is _______.- a)1
- b)2
- c)5
- d)3
Correct answer is option 'D'. Can you explain this answer?
An neutral element A has 3 electrons, the atomic number of an element is _______.
a)
1
b)
2
c)
5
d)
3
|
|
Rudraksh Saha answered |
If the number of electrons is 1, 2, or 3 then the atomic number will respectively be 1, 2, or 3.
if the number of electrons is 5, 6, or 7 then the atomic number will respectively be 5, 6, or 7.
if the number of electrons is 4 then the atomic number will respectively be 4.
if the number of electrons is 8 then the atomic number will respectively be 0.
Find the symbol of an element X, if its mass number is A and atomic number is Z respectively.- a)AXZ
- b)AZX
- c)ZAX
- d)ZXA
Correct answer is option 'B'. Can you explain this answer?
Find the symbol of an element X, if its mass number is A and atomic number is Z respectively.
a)
AXZ
b)
AZX
c)
ZAX
d)
ZXA
|
Parth Khanna answered |
Answer:
The symbol of an element X, given its mass number A and atomic number Z, is represented as AZX. Let's break down the symbol to understand why option 'B' is the correct answer.
Understanding the symbol:
- A represents the mass number of the element, which is the sum of the protons and neutrons in the nucleus of an atom.
- Z represents the atomic number of the element, which is the number of protons in the nucleus of an atom.
- X represents the chemical symbol of the element, which is a one or two-letter abbreviation used to represent an element.
Explanation of the correct answer:
Option 'B' is the correct answer because it follows the correct order of the elements in the symbol.
- A is the mass number, which represents the total number of protons and neutrons in the nucleus of the atom. It should come before Z.
- Z is the atomic number, which represents the number of protons in the nucleus of the atom. It should come after A.
- X is the chemical symbol, which represents the element. It should come at the end.
Therefore, the correct symbol of the element X, given its mass number A and atomic number Z, is AZX.
Explanation of incorrect options:
- Option 'A' (AXZ) is incorrect because it does not follow the correct order of the elements in the symbol. The mass number should come first, followed by the atomic number, and then the chemical symbol.
- Option 'C' (ZAX) is incorrect because it reverses the order of the elements in the symbol. The atomic number should come before the chemical symbol.
- Option 'D' (ZXA) is incorrect because it also reverses the order of the elements in the symbol. The atomic number should come before the chemical symbol.
Conclusion:
The correct symbol of an element X, given its mass number A and atomic number Z, is represented as AZX. It is important to follow the correct order of the elements in the symbol to accurately represent the element.
The symbol of an element X, given its mass number A and atomic number Z, is represented as AZX. Let's break down the symbol to understand why option 'B' is the correct answer.
Understanding the symbol:
- A represents the mass number of the element, which is the sum of the protons and neutrons in the nucleus of an atom.
- Z represents the atomic number of the element, which is the number of protons in the nucleus of an atom.
- X represents the chemical symbol of the element, which is a one or two-letter abbreviation used to represent an element.
Explanation of the correct answer:
Option 'B' is the correct answer because it follows the correct order of the elements in the symbol.
- A is the mass number, which represents the total number of protons and neutrons in the nucleus of the atom. It should come before Z.
- Z is the atomic number, which represents the number of protons in the nucleus of the atom. It should come after A.
- X is the chemical symbol, which represents the element. It should come at the end.
Therefore, the correct symbol of the element X, given its mass number A and atomic number Z, is AZX.
Explanation of incorrect options:
- Option 'A' (AXZ) is incorrect because it does not follow the correct order of the elements in the symbol. The mass number should come first, followed by the atomic number, and then the chemical symbol.
- Option 'C' (ZAX) is incorrect because it reverses the order of the elements in the symbol. The atomic number should come before the chemical symbol.
- Option 'D' (ZXA) is incorrect because it also reverses the order of the elements in the symbol. The atomic number should come before the chemical symbol.
Conclusion:
The correct symbol of an element X, given its mass number A and atomic number Z, is represented as AZX. It is important to follow the correct order of the elements in the symbol to accurately represent the element.
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