Advertisements
Advertisements
प्रश्न
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.
उत्तर
- Atoms with no electron will have mass, because mass depends on number of Protons and Neutrons though it has no electron.
- Atoms can exist without electrons, Matter is build out of neutrons, protons (+) and electrons (-). Matter becomes stable only if it is electrically neutral.
- So atoms without electrons do exist and must have their own states (charged or uncharged transfered back and forth in their environment)
- Example: He2+. It has 2 protons and 2 neutrons but no electrons.
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
TRUE \ FALSE
Elements having a tendency to accept electrons are called metals
TRUE \ FALSE
Cathode rays are a stream of fast moving particles that travel in random directions.
WRITE SHORT ANSWER
What is radioactivity?
WRITE SHORT ANSWER
Name three inert gases.
ANSWER IN DETAIL
Enlist the features of Bohr’s model of an atom. How did he correct the Rutherford’s model ?
Write the names of `"Na"_3"PO"_4` compounds :
Define: Mass number
Name two particles found inside the nucleus. What are they collectively called ?
Name three non-metals/radicals which have valency -1, -2, and -3.
An atom has 13 protons and 14 neutrons.
How many electrons would be present in this atom ?
Fill in the blank
If an atom loses an electron, it acquires ______ a charge.
What value has been given to the mass of this reference atom ?
What is an atom ? How do atoms usually exist ?
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.
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.
Electron, proton, neutron are the types of ______ in an atom.
Draw the electron dot structure of this compound.
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.
Select the correct answer to the statement given below:
Imaginary path around the nucleus of an atom in which electrons revolve.
Draw the structure of an atom and explain the position of the sub-atomic particles.
Define the following term with an example.
Metal
Does the solubility of a substance change with temperature? Explain with the help of an example.
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?
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
- Rutherford’s atomic model
- Thomson’s atomic model
- Bohr’s atomic model
Write any two observations which support the fact that atoms are divisible.
Lead is also known as plumbum.
What is the fundamental particle of an element?
What are the 3 most abundant atoms on the earth?
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 ______.
