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प्रश्न
Define the following term with an example.
Metal
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उत्तर
Metal: A chemical element that is an effective conductor of electricity and heat can be defined as a metal.
Ex.: Copper, Iron, Silver, etc.
APPEARS IN
संबंधित प्रश्न
MATCH THE COLUMNAS
| 1. Jpham Dalton | a. Neutrons |
| 2. Atom | b. Model of the atom |
| 3. Chadwick | c.The atomic theory of matter |
| 4. Rutherfrod | d. Positively charged |
| 5. Protons | e. Electricity neutral |
| 6. Nuclear fusion | f. Generator of electricity |
| 7.Gamma -rays | g. High penetrating power |
| h.Energy in sun |
WRITE SHORT ANSWER
What is radioactivity?
WRITE SHORT ANSWER
Name three inert gases.
Define:- Molecule
Write the names of the elements present in the :-
Sulphuric acid
Fill in the blank
An ion with negative charge is called _______
Define: Relative atomic mass
Give the charge and the mass of an electron, proton and neutron present in an atom ?
Write electronic configuration of oxygen, fluorine, sodium, silicon, argon.
An atom has 13 protons and 14 neutrons.
What is the atomic mass of the atom ?
What are the building blocks of matter ?
How is the size of an atom indicated ?
What value has been given to the mass of this reference atom ?
Is it possible to see atoms these days ? Explain your answer.
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 ?
Find the mass of 2 moles of nitrogen atoms.
Match the pairs.
| Group 'A' | Group 'B' |
| a. Proton | i. Negatively charged |
| b. Electron | ii. Neutral |
| c. Neutron | iii. Positively charged |
Draw the electron dot structure of this compound.
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
What will be the charge present of the molecule XY after chemical combination?
Name 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.
The volume occupied by 1 mole of a diatomic gas at S.T.P is ______
Atoms of different elements having the same number of ______ are called isotones.
Atoms of one element can be transmuted into atoms of other elements by ______
You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?
Dalton’s atomic theory successfully explained
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportions
A small block slides down on a smooth inclined plane, starting from rest at time t = 0. Let Sn be the distance travelled by the block in the interval t = n – 1 to t = n. Then, the ratio `S_n/(S_(n + 1))` is ______.
