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प्रश्न
Define the following term:
Atom
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उत्तर
An atom is the smallest particle of an element which retains its chemical identity in all physical and chemical changes.
संबंधित प्रश्न
Tick the most appropriate answer.
Who discovered that radioactive rays are given out by uranium?
- Henri Becquerel
- Marie Curie
- Pierre Curie
- Schmidt
Define:- Radicals
Write the names of the elements present in the:-
Acetic acid
What is the maximum number of electrons present in:
1. first shell
2. second shell
3. third shell and
4. fourth shell
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is such a particle called ?
Fill in the following blanks with suitable words :
In water, the proportion of oxygen and hydrogen is .............. by mass.
An atom of an element X may be written as `""_9^4"X"`
(a) What does the figure 9 indicate?
(b) What does the figure 4 indicate?
(c) What is the number of protons in atom X?
(d) What is the number of neutrons in atom X?
(e) What is the number of electrons in atom X?
(f) How many electrons are there in the outermost shell of an atom of element X?
(g) Write the symbol of ion formed by an atom of element X.
For the symbols H, D and T, write the subatomic particles (protons, neutrons and electrons) found in each one of them.
Give brief information of three subatomic particles with reference to electrical charge, mass and location.
Draw diagrams representing the atomic structures of the following:
- Sodium atom
- Chlorine ion
- Carbon atom
- Oxygen ion
Draw the diagrams representing the atomic structures of the following: Neon
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
Which element will lose electron?
Draw the basic structure of an atom representing its –
- Subatomic particles
- Nucleus
- Orbits or shells.
Select the correct answer to the statement given below:
The smallest particle of a substance – capable of independent existence and which retains the characteristics of the substance.
Rewrite the given sentence in correct form.
Elements contain two or more kind of atoms and compounds contain only one kind of atom.
A sample of vitamic C is known to contain 2.58 ×1024 oxygen atoms. How many moles of oxygen atoms are present in the sample?
The graphite refill used is pencil is made of element called ______.
The ______ are combination of atoms of various elements or the same element.
