Nicotine has two rings and m+=162.1157 by high-resolution mass spectroscopy. give the molecular formula for nicotine and calculate the number of double bonds.

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

Particles vibrate in a rigid structure and do not move relative to their neighbors.