Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The mass number of a nucleus is?
Always less than its atomic number
The sum of the number of protons and neutrons present in the nucleus
Always more than the atomic weight
A fraction
Correct answer is B
mass number, is the sum of the numbers of protons and neutrons present in the nucleus of an atom.
The reactivity of fluorine is due to?
its high electro negativity
small size of fluorine atom
availability of D-orbitals
strong f-f bond
Correct answer is A
fluorine (F), most reactive chemical element and the lightest member of the halogen elements.
As the most electronegative element, it is extremely reactive.
Soaps clean surfaces on the principle based on?
viscosity
floatation
elasticity
surface tension
Correct answer is D
Since the surface tension forces become smaller as the distance between water molecules increases, the intervening soap molecules decrease the surface tension.
I only
I, II and IV
I and II only
I, II, III, and IV
Correct answer is D
- Calcium trioxocarbonate (IV) occurs abundantly in earth's crust as limestone, chalk and marble
- Eggshell is made almost entirely of calcium carbonate (CaCO3) crystals.
James Chadwick
Ernest Rutherford
J.J Thompson
John Dalton
Correct answer is A
- Sir James Chadwick, was a British physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932.
- Ernest Rutherford postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay.
- Sir Joseph John Thomson was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered.
- John Dalton was an English chemist, physicist and meteorologist. He is best known for introducing the atomic theory into chemistry