What is the mass number of an element if its atom contains 10 protons, 10 electrons and 12 neutrons?
32
22
20
10
Correct answer is B
No explanation has been provided for this answer.
Allotropes of an element differ in their
physical properties
chemical properties
mass numbers
electronic configuration
Correct answer is A
No explanation has been provided for this answer.
A plastic which cannot be softened by heat is described as
thermosetting
non-biodegradable
thermoplastic
malleable
Correct answer is A
No explanation has been provided for this answer.
Biotechnology is applied in the following except
baking industry
wine production
production of antibiotics
manufacture of soap
Correct answer is D
No explanation has been provided for this answer.
20 mol dm-3
0.40 mol dm-3
2.00 mol dm-3
5.00 mol dm -3
Correct answer is B
From M1V1 = M 2
V2; m 1 = 0.50 mol dm-3; m2 = ?; v1 = 80cm 3 = 100cm3
:. m2 = m1v2/v2 = 0.50 x 80/100 = 0.40 mol dm-3