Question

• Identify the pair in which the following rule for writing symbols is not needed.
"If the first two letters of the names of the elements are same, then the symbol consists of
first letter and second or third letter of English name that they do not have in common."
a. Argon - Ar; Arsenic - As
b. Cobalt - Co; Copper - Cu
C. Calcium - Ca; Cadmium - Cd
d. Magnesium - Mg; Manganese – Mn​

Answer 1

I don't know

what is this

Answer 2

Answer:

the answer is B

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