Question Text
Question 1 :
Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ______ and _______ respectively.
Question 2 :
In a sample of ethyl ethanoate ($CH_{3}COOC_{2}H_{5}$) the two oxygen atoms have the same number of electrons but different number of neutrons. Which of the following is the correct reason for it?
Question 3 :
Which of the following element has an atom with one electron, one proton and no neutron ?
Question 5 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
Question 8 :
Which of the following correctly represent the electronic distribution in the Mg atom?
Question 9 :
Which of the following scientist identified the 'Neutron' in the structure of an atom ?
Question 10 :
Which of the following is true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic mass = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons.
Question 12 :
What is the metal which exists in the liquid state at room temperature?
Question 13 :
You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?
Question 14 :
What is the SI prefix for $10^{-6}$ multiples and submultiples of a unit?
Question 19 :
Why is it not possible to see an atom with naked eyes?
Question 20 :
Which has more number of atoms? 100g of $N_2$ or 100 g of $NH_3$.