1) give reasons :
(a) steam produces more severe burns than boiling water.
(b) we are able to sip hot tea faster from a saucer rather than a cup.
(c) water kept in an earthen pot becomes cool during summer.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

the answer is 0.8m.

by: nicholas