Q. Symbol and element name of 110-118 atomic number symbol.
You must have noticed in the periodic table that 110-118 elements have Uun, Uuu, Uub...symbol in the periodic table.
A. Uun, Uuu, Uub all are IUPAC nomenclature of 110, 111, 112 respectively. You will this in this concept.
Q. Why do elements show different properties like odor, appearance, reactions, etc?
A. Because all elements are different from each other in respective their mass, number of electrons, atomic number, etc. Every
element has unique and different properties.
You just finished â€œSome basic concepts in chemistryâ€ In this chapter, you have completed:
(a) 16 concepts
(b) 13 doubts
(c) 43 number of questions
(d) 61 number of examples
Firstly you read some basic concepts like Daltonâ€™s Atomic Theory and Laws of Chemical combinations then finally you moved to the
Mole concept and molarity and normality.
By studying this chapter, you have secured 3.5% weightage of complete chemistry syllabus and thus you have accomplished a
solid foundation stone in your preparation journey as well.
Make sure you practice more and more to achieve what you desire. Revision is the most important part so, donâ€™t forget to do it and
keep writing mock tests regularly.
Keep it up !!!!
Q. Why do soaps not form lather in hard water?
A. Hard water has various soluble salts of magnesium and calcium due to which the soaps are not able to form lather whereas soft
water does not have these salts thus soaps make lather in soft water.
Q. What is the difference between molarity and normality?
A. Molarity is the concentration measurement for any amount of substance present in 1 litre of solution. Normality is also the
concentration measurement but it measures the number of equivalents of solute present in 1 litre of solution.
What is the difference between empirical formula and molecular formula?
A. Empirical formula is the simplest ratio of atoms present in the molecule like CH O while the molecular formula is the
representation of the actual number of atoms present in the molecule.
Q. What is the difference between atomic mass and molecular mass?
A. Atomic mass is the mass of a single atom or in other words, it is equal to the number of protons and neutrons.
Molecular mass is the mass of all the atoms combined in the molecule.
Q. How was Avogadro number discovered?
A. It was discovered by measuring the 12g of C-12 carbon isotope. The number of atoms of carbon in this quantity was 6.022 x
10 . This number was known as Avogadro number.
Q. Let's think about why there are three units to measure temperature.
A. We know about K, C, and F. All three units are used in different places. For example, Fahrenheit is used to measure body
temperature, celsius is used to measure environment temperature and kelvin is used to make calculations.