An administrator is having some trouble with a disk partition and needs to do maintenance on this partition but their user's home directories are on it and several are logged in. which of the following commands would disconnect the users and allow the administrator to safely execute maintenance tasks?

a. halt 1
b. init 1
c. logout --all now
d. runlevel 1
e. shutdown --maintenance now

answer: when the substance contain the two parts (polar and non-polar) like soap.

explanation:

soap is produced from the basic hydrolysis of ester "saponification", it is considered as a salt of hydrocarbons. the soap molecule contains the two parts: a polar group   (-coo-na+) and a non-polar group (r-hydrocarbon part). the polar group is called the head and the tail is the non-polar group. the polar group is hydrophilic in nature (water loving) and the non-polar group is hydrophobic in nature (water repelling).the polar/non-polar nature of a substance is useful that it can dissolve the non-polar substances by the polar part and also can dissolve the polar substances by the non-polar part. it commonly used in detergents and soaps.