Advertisements
Advertisements
Question
Show diagrammatically the electron distributions in a sodium atom and a sodium ion and also give their atomic number.
Advertisements
Solution
11Na -2,8,1 (11 electrons)
Na – 1e–—> Na+ (10 electrons) Electronic configuration 2, 8.
The atomic number of an element is equal to the number of protons in its atom. Since, sodium atom and sodium ion contain the same number of protons, therefore, the atomic number of both is 11.
APPEARS IN
RELATED QUESTIONS
What are the atomic numbers of elements whose outermost electrons is represented by 3s1.
The mass number of an element is 18. It contains 7 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it? What is the atomic number of the element?
From the symbol `""_15^31"P"`, state :
(i) mass number of phosphorus,
(ii) atomic number of phosphorus, and
(iii) electron configuration of phosphorus.
What is the significance of atomic numbers in the modern Periodic Table?
If an atom ‘A’ has atomic number 19 and mass number 39, state –
- Its electronic configuration.
- The number of valence electrons it possesses.
Draw the atomic diagram of the following element showing the distribution of – protons, neutrons and the electrons in the various shell of the atom.
Calcium – \[\ce{^40_20Ca}\]
[The upper number represent the – mass number and the lower number represent the – atomic number e.g. calcium – mass number = 40, atomic number = 20]
‘Valency is the number of hydrogen atoms which can combine with [or displace] one atom of the element [or radical] forming a compound’. With reference to the above definition of valency, state the valency of chlorine in hydrogen chloride, giving reasons.
Which of the following are true for an element?
- Atomic number = number of protons + number of electrons
- Mass number = number of protons + number of neutrons
- Atomic mass = number of protons = number of neutrons
- Atomic number = number of protons = number of electrons
Name the 3 sub-atomic particles of an atom.
