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प्रश्न
State the meaning of the term – (a) atom, (b) molecule, (c) radical – with a suitable example.
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उत्तर
(a) Atom: It is the smallest particle of an element, which is made up of only one kind of atom. Atoms are built up of sub-atomic particles protons, neutrons, and electrons.
Example: O - Oxygen atom, H - Hydrogen atom
(b) Molecule: “The smallest particle of a substance which can exist on its own and retains the physical and chemical properties of the substance is called a molecule.”
Example: O2 - Oxygen molecule, H2O - Water molecule
(c) Radical: A radical is an atom of an element or a group of atoms of different elements that behaves as a single unit with a positive or negative charge on it.
Example: \[\ce{NH^+4}\] - Ammonium radical
APPEARS IN
संबंधित प्रश्न
Tick the most appropriate answer.
Who discovered that radioactive rays are given out by uranium?
- Henri Becquerel
- Marie Curie
- Pierre Curie
- Schmidt
WRITE SHORT ANSWER
What is radioactivity?
Define: Mass number
Name the particle or particles you would expect to find in :
The orbit of an atom
Name the particle or particles you would expect to find in :
The nucleus of an atom
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
Does the particle have an excess of electrons or a deficiency of electrons ?
Fill in the blank
If an atom loses an electron, it acquires ______ a charge.
Fill in the blank
A charged particle is called an _____
Write the full form of IUPAC.
The electronic configuration of an element Z is 2, 8, 8.
(a) What is the atomic number of the element?
(b) State whether element Z is a metal or a non-metal.
(c) What type of ion (if any) will be formed by an atom of element Z? Why?
(d) What is special about the outermost electron shell of the atom of this element?
(e) Give the name and symbol of element Z.
(f) Name the group of elements to which Z belongs.
For the symbols H, D and T, write the subatomic particles (protons, neutrons and electrons) found in each one of them.
Which of the following statement is correct about the atom of an element ?
Draw the electron dot structure of this compound.
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
Which element will lose electron?
A compound containing one atom of carbon and two atoms of oxygen is ______.
Draw the structure of an atom and explain the position of the sub-atomic particles.
Project.
To have an idea of what atoms are, students can be asked to construct atoms using pipe cleaners (thin metal wires-electron shells), pompoms (balls-different colours for protons and neutrons) and beads (electrons). Students will love and enjoy putting them together and they look great hanging from the ceiling in the classroom.
Give the salient features of “Modern atomic theory”.
You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?
