The melting and boiling points of the Group 1 elements decrease on descending the group. This is due to a decrease in the forces of attraction between the atoms. On crossing a period in the Periodic Table the atomic size decreases. On descending a group the atomic size increases.
<h3><em /></h3><h3><em /></h3><h3><em>Hope this helped! Have a great day</em></h3>
heated crude oil enters a tall fractionating column , which is hot at the bottom and gets cooler towards the top. vapours from the oil rise through the column. vapours condense when they become cool enough.
