Advertisements
Advertisements
प्रश्न
K: Potassium:: C: ______.
Advertisements
उत्तर
K: Potassium:: C: Carbon.
APPEARS IN
संबंधित प्रश्न
The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes `""_8^16X" and """_8^18X` in the sample?
TRUE \ FALSE
Cathode rays are a stream of fast moving particles that travel in random directions.
WRITE SHORT ANSWER
What is radioactivity?
ANSWER IN DETAIL
State the postulates of the Dalton’s atomic theory.
Write the names of the elements present in the :-
Sulphuric acid
Write the names of `"Ca"("NO"_3)_2` compounds :
State Dalton’s atomic theory.
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is the mass number of X?
How many times is a proton heavier than an electron?
What is an atom ? How do atoms usually exist ?
An atom of element E contains 3 protons, 3 electrons and 4 neutrons :
(a) What is its atomic number?
(b) What is its mass number?
(c) Write the electronic configuration of the element E.
(d) State whether element E is a metal or non-metal. Why?
(e) What type of ion, cation or anion, will be formed by an atom of element E? Why
(f) Write the symbol of the ion formed by an atom of element E.
(g) What could element X be?
For the symbols H, D and T, write the subatomic particles (protons, neutrons and electrons) found in each one of them.
Deduce from the datum provided.
| Datum | To deduce |
| \[\ce{_11^23Na}\] | Neutron number |
| \[\ce{_6^14C}\] | Mass number |
| \[\ce{_17^37 Cl}\] | Proton number |
Draw the electron dot structure of this compound.
An atom of an element has no electron. Will that atom have any mass or not? Can an atom exist without electron? If so then give example.
Define the following term with an example.
Metalloid
The smallest unit of an element is ______.
______ is a substance that is made up of three oxygen atoms chemically combined.
Lead is also known as plumbum.
