How many neutrons does element x have if its atomic number is 46 and its mass number is 159

Several kinds of bears are found on earth. most bears are brown or black, but one type of bear, the polar bear, is white. what process led to this difference in fur color? explain your answer.

All of the following are part of the biosphere except

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