The main difference between a safety valve and a pressure relief valve is: (a) safety valves are suited for all fluids, whereas pressure relief valves are designed to 4 operate with gases only (b) pressure relief valves are designed to operate with liquids only whereas safety valves can handle all fluids. (c) safety valves are designed for gases only and pressure relief valves will only handle liquids. (d) pressure relief valves are designed to handle gases and safety valves are designed handle only liquids. to

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.