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प्रश्न
From the symbol \[\ce{^4_2He}\] for the element helium, write down the mass number and the atomic number of the element.
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उत्तर
\[\ce{_{Atomic number} ^4_2He ^{mass number}}\]
- Mass number – 4
- Atomic number – 2
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संबंधित प्रश्न
Which of the following are isoelectronic species i.e., those having the same number of electrons?
Na+, K+, Mg2+, Ca2+, S2–, Ar
Write true or false for the following statement
An atom on the whole has a positive charge.
WRITE SHORT ANSWER
Define the atomic mass number of an atom.
The atom of an element is made up of 4 protons, 5 neutrons and 4 electrons. What are its atomic number and mass number?
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.
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]
Atomic number : ______ :: Mass number : Number of protons and neutrons.
The particles that make up the atom are called ______ particles.
Every atom has an equal number of protons and electrons. The nature of the atom is ______.
An element has 2 electrons in its N shell.
- What is its atomic number?
- State its position in the periodic table.
- Is it a metal or a non-metal?
- State the name assigned to this group.
- What is the valency of this element?
