Advertisements
Advertisements
Question
An element with mass number 81 contains 31.7% more neutrons as compared to protons. Assign the atomic symbol.
Solution
Let the number of protons in the element be x.
∴ Number of neutrons in the element
= x + 31.7% of x
= x + 0.317 x
= 1.317 x
According to the question,
Mass number of the element = 81
∴ (Number of protons + number of neutrons) = 81
`=> x + 1.317x = 81`
`2.317x = 81`
`x = 81/2.317`
= 34.95
`therefore x = 35`
Hence, the number of protons in the element i.e., x is 35.
Since the atomic number of an atom is defined as the number of protons present in its nucleus, the atomic number of the given element is 35.
∴ The atomic symbol of the element is `""_35^81"Br"`
APPEARS IN
RELATED QUESTIONS
Define the atomic mass unit.
A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.
An ion with mass number 37 possesses one unit of negative charge. If the ion contains 11.1% more neutrons than the electrons, find the symbol of the ion.
An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. Assign the symbol to this ion.
Define gram atomic mass of a substance. How much is the gram atomic mass of oxygen ?
Define atomic mass of an element.
Explain the need for a reference atom for atomic mass. Give some information about two reference atoms.
What is meant by Unified Atomic Mass?
Define the following form:
Atomic mass number
What are polyatomic ions? Give two examples.
Define atomic mass unit.
A hydrocarbon contains 4.8g of carbon per gram of hydrogen. Calculate the gram atom of each.
Give a reason for the following:
The mass number of an atom is slightly less than the actual atomic mass.
The sum of the numbers of protons and neutrons of an atom is called its ______
Noble gases are Diatomic.
Answer the following question using the data given below:
- Assertion: The Relative Atomic mass of aluminium is 27
- Reason: An atom of aluminium is 27 times heavier than 1/12th of the mass of the C – 12 atom.
Write the different types of isotopes of oxygen and their percentage abundance.
Calculate the % of each element in calcium carbonate. (Atomic mass: C-12, O-16, Ca -40)
Calculate the % of oxygen in Al2(SO4)3. (Atomic mass: Al-27, O-16, S -32)
One electron is present in the outermost shell of the atom of an element X. What would be the nature and value of charge on the ion formed if this electron is removed from the outermost shell?
What are the postulates of Bohr’s model of an atom?
Chlorine exists in two isotopic forms, \[\ce{Cl-37}\] and \[\ce{Cl-35}\] but its atomic mass is 35.5. This indicates the ratio of \[\ce{Cl-37}\] and \[\ce{Cl-35}\] is approximately
An atom having atomic mass number 13 has 7 neutrons. What is the atomic number of the atom?
Atoms are so tiny their mass number cannot be expressed in grams but expressed in ______.
The ratio of masses of H and O in H2O is ______.
If the atomic mass unit ‘u’ were defined to be `1/5 "th"` of the mass of an atom of C-12, what would be the atomic weight of nitrogen in amu or ‘u’ in this state? Atomic weight of N on the conventional scale is 14.
