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.
Helium is often used in observation balloons because it is?
light and combustible
light and non-combustible
heavy and combustible
heavy and non-combustible
Correct answer is B
No explanation has been provided for this answer.
Which of the following statements is FALSE about isotopes of the same element?
They have the same number of electrons in their outermost shells
They have different atomic masses
They have the same atomic number and the number of electrons
They have the same atomic number but different umber of elelctrons
Correct answer is D
No explanation has been provided for this answer.
The ability of ionic solids is generally due to the?
negative electron affinity of most atoms
crystal lattice forces
electron pair sharing
positive ionization potentials
Correct answer is B
No explanation has been provided for this answer.
In the oil drop experiment, Millikan determined the?
charge to mass ratio of the electron
mass of the electron
charge of the electron
mass of the proton
Correct answer is C
No explanation has been provided for this answer.
A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as?
O
O+
N
O-
Correct answer is B
The atomic number is the number of protons in the nucleus of an atom.
The number of protons define the identity of an element (i.e., an element with 8 protons is a carbon atom, no matter how many neutrons may be present).
If an atom loses or gains electrons, it will become a positively or negatively charged particle, called an ion.
The loss of one or more electrons results in more protons than electrons and an overall positively charged ion, called a cation.