What are 5 main chemicals that make all living things?

According to the law of conservation of energy, energy can neither be created nor destroyed. if this is true, why is there less energy in the top of the energy pyramid than there is in the bottom of the energy pyramid?

Identify the examples in which sam interacts only with natural resources

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.