Advertisements
Advertisements
Question
Who originated the word ‘atom’ ?
Advertisements
Solution
Democritus
APPEARS IN
RELATED QUESTIONS
If bromine atom is available in the form of, say, two isotopes `""_35^79Br (49.7%)" and """_35^81Br (50.3%)`, calculate the average atomic mass of bromine atom.
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:- Radicals
Write the names of the elements present in the:-
Sodium hydroxide
State Dalton’s atomic theory.
How did Neils Bohr visualise the atom ?
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.
How many times is a proton heavier than an electron?
Define the following term:
Atom
Match the pairs.
| Group 'A' | Group 'B' |
| a. Proton | i. Negatively charged |
| b. Electron | ii. Neutral |
| c. Neutron | iii. Positively charged |
Compare:
Chlorine atom and chloride ion, with respect to
Atomic structure
Electrical state
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 will form positive ion?
A radical take part – unsplit in a chemical reaction and retains its identity in reactions.
With reference to the radical –
- ammonium
- bisulphate
- carbonate
state the group of atoms present in each radical.
The smallest particle of matter that can exist by itself is ______.
A compound containing one atom of carbon and two atoms of oxygen is ______.
______ is a substance that is made up of three oxygen atoms chemically combined.
