Advertisements
Advertisements
Question
Define: Relative atomic mass
Advertisements
Solution 1
Relative atomic mass— Relative atomic mass is the mass of an atom of an element as a multiple of the standard atomic mass unit.
Solution 2
The relative atomic mass of an element is the ratio between the average mass of its isotopes to 1/12th part of the mass of a carbon – 12 atoms. It is denoted as Ar.
Relative atomic mass = `" Average mass of the isotopes of the element"/(1"/"12^{"th"}" of the mass of one Carbon- 12 atom")`
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.
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 |
ANSWER IN DETAIL
Enlist the features of Bohr’s model of an atom. How did he correct the Rutherford’s model ?
Define:- Radicals
Write the names of the elements present in the:-
Acetic acid
Fill in the blank:
Atoms are _____
Give the charge and the mass of an electron, proton and neutron present in 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 ?
Name the three subatomic particles present in an atom.
Why is it not possible to see an atom even with the most powerful microscope ?
Dalton's atomic theory says that atoms are indivisible. Is this statement still valid ? Give reasons for your answer.
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.
Deduce from the datum provided.
| Datum | To deduce |
| \[\ce{_11^23Na}\] | Neutron number |
| \[\ce{_6^14C}\] | Mass number |
| \[\ce{_17^37 Cl}\] | Proton number |
Elements X and Y have 1 and 7 electrons in their outermost shell respectively.
Which element will gain electron?
State the meaning of the term – (a) atom, (b) molecule, (c) radical – with a suitable example.
Select the correct answer to the statement given below:
Imaginary path around the nucleus of an atom in which electrons revolve.
Rewrite the given sentence in correct form.
Elements contain two or more kind of atoms and compounds contain only one kind of atom.
State true or false. If false, correct the statement.
The basic unit of an element is molecule.
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.
Define the following term with an example.
Metalloid
Which of the following statements made by Dalton has not undergone any change?
An element is composed of ______ atoms.
The number of atoms present in a molecule is called its ______.
Which of the following has maximum number of atoms?
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?
What is the fundamental particle of an element?
