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.
Which metal is a constituent of both bronze and solder?
copper
lead
silver
tin
zinc
Correct answer is D
No explanation has been provided for this answer.
0
2
3
4
5
Correct answer is E
You can determine the group of an element by the number of electrons of their outermost shell.
Hence; this element silicon belongs to group 5 OR The Group to which an element belongs to, can be identified by adding the number of electrons of the orbital with the highest principal quantum number, in this case, 3s2 and 3p3. Therefore, 2+3 is equal to 5
note; if the highest principal quantum number is just 3s2 for example then the element belong to group 2.
6.89g
6.93g
6.98g
7.04g
7.12g
Correct answer is C
No explanation has been provided for this answer.
6
6.8
6.9
7
7.1
Correct answer is C
the relative atomic mass of lithium = percentage abundance times the mass number of the first isotope + percentage abundance times the mass number of the second isotope.
the relative atomic mass of lithium = ( \(\frac{90}{100} \times7 + \frac{10}{100} \times 6\)) =(( 0.9 x 7) + (0.1 x 6)) = 6.3 + 0.6 = 6.9.
Why does the treatment of cotton fabrics with dilute acids weaken the materials?
Cotton is hydrolysed completely to glucose
The fabrics are soluble in dilute acids
The molecular chains are partially broken
The molecular chain length f the fabric increases
The thread holding the fabric together Is completely destroyed.
Correct answer is C
No explanation has been provided for this answer.