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.
Atoms are electrically neutral because they
do not conduct electricity
contain equal number of protons and electrons
are composed of neutrons and electrons
cannot be attracted by electromagnetic field.
Correct answer is B
Atoms are electrically neutral because they contain equal amount of positive and negative charge. This is because they have equal number of protons and electrons.
42
45
126
180
Correct answer is D
Molecular formula = (empirical formula x n)
where n= (1,2,3,...)
\(CH_{2}O = 12 + (2\times 1) + 16 = 30\)
Relative molecular mass = (30 x n)
From the options, only 180 is a multiple of 30, when n=6.
The law of definite proportions states that
pure samples of the same compound contain the same elements combined in the same proportion by mass
pure samples of substances are in the same proportion by mass
chemical compounds are pure because they contain the same elements
matter can neither be created nor destroyed.
Correct answer is A
The Law of Definite Proportions states that all pure samples of a particular chemical compound contain similar elements combined in the same proportion by mass.
1:1
1:2
2:1
2:3
Correct answer is A
1g of Hydrocarbon = 0.93g of Carbon, therefore, Hydrogen = (1 - 0.93)g = 0.07g
C : H
0.93 : 0.07
\(\frac{0.93}{12}\) : \(\frac{0.07}{1}\)
0.078 : 0.07
\(\frac{0.078}{0.07} : \frac{0.07}{0.07}\)
\(\approxeq 1:1\)
Which of the following statements is true about ionic radius? Ionic radius
increases as nuclear charge increases
decreases as nuclear charge increases
decreases as nuclear charge decreases
remains constant as nuclear charge increases
Correct answer is B
No explanation has been provided for this answer.