No :- CuCl is correct.
1 is not a Roman numeral, you numeral should be written as XVIII and it represents the number 18
That already is a roman numeral.
1986 but it should be written as MDCCCCLXXXVI or VXMMI.
95 but according to today's rules it should be written as XCV
Generally the Roman numeral IV represents the number 4 but on some old watches and sun dials 4 is represented by the numeral IIII. The numeral IIII was correct when it was written but convention now decrees that a numeral should not be repeated more than three times. According to this rule IIII should no longer be used.
1 is not a Roman numeral, you numeral should be written as XVIII and it represents the number 18
That already is a roman numeral.
1986 but it should be written as MDCCCCLXXXVI or VXMMI.
4, as a Roman Numeral, should be written as IV, although I have seen it occassionally written as IIII. I think both are valid, but generally 4 is IV .
95 but according to today's rules it should be written as XCV
The numbers 1 through 10 should be written out as: One, Two, Three ... etc. From the numeral "11" and beyond, they can be written as numbers.
Generally the Roman numeral IV represents the number 4 but on some old watches and sun dials 4 is represented by the numeral IIII. The numeral IIII was correct when it was written but convention now decrees that a numeral should not be repeated more than three times. According to this rule IIII should no longer be used.
Some Roman numeral clocks use IIII to represent 4, which is how most Romans would have written it. However, in order to comply with the rule that no numeral should be writen more than three times in succession the number 4 is now more correctly written as IV.
DDXCIX is not a real Roman numeral. D = 500 and DD if it existed would mean 500 + 500, which is 1000 but there is a Roman numeral for 1000, which is M, so the combination of DD would never be used. The numeral should be written as MXCIX and it represents 1099.
That is not formatted properly. At best guess, it should be written as CXV, which would be 115. But it could be XCV, which would be 95.
It means that the numeral is to be multiplied by a thousand. For example, X = 10 but with a line over X it would be 10,000. A horizontal line above a numeral means that it should be multiplied by a thousand so VII with a line above it represents 7000, it can also be written as (VII)
The chemical formula of decane is C10H22.