Advertisements
Advertisements
Question
Differentiate between the following term:
Atomic number and mass number
Advertisements
Solution
Differentiate between:
Atomic number:
- Z is the number of protons or the number of electrons in an atom.
- Present in nucleus = P
Present in orbits = e
Mass number:
- A is the sum of protons and neutrons.
- Present in the nucleus of an atom.
APPEARS IN
RELATED QUESTIONS
The atomic number and the mass number of sodium are 11 and 23 respectively. What information is conveyed by this statement.
Name the particles which actually determine the mass of an atom.
Fill in the blanks- The number of protons in the nucleus of an atom is called its ....................
(a) Which of the nuclear particles is present in the same fixed number in the atoms of any particular element?
(b) What do we call this number which is characteristic of a particular element?
What are orbits or shells of an atom?
Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.
Oxygen – \[\ce{^16_8O}\]
[The upper number represent the – mass number and the lower number represent the – atomic number e.g. calcium – mass number = 40, atomic number = 20]
Draw the structure of the following atoms showing the nucleus containing – protons, neutrons and the orbits with the respective electron:
Carbon [At. no. = 6, Mass no. = 12]
Elements A, B and C have atomic numbers 9, 20 and 10 respectively.
- State which one is
(1) a non-metal,
(2) a metal,
(3) chemically inert.[A,B,C] - Write down the formula of the compound formed by two of the above elements.[BA2]
What is common salt? Name the elements present in it. Write the formula of common salt. What are the atomic number and the mass number of the elements? Write the ions in the compound.
The ratio of the radii of hydrogen atom and its nucleus is ~ 105. Assuming the atom and the nucleus to be spherical,
- what will be the ratio of their sizes?
- If atom is represented by planet earth ‘Re ’ = 6.4 ×106 m, estimate the size of the nucleus.
