Which of the following occurs when an electron moves from a higher energy shell to a lower energy shell? a. a neutron is always lost. b. a proton is always gained. c. energy is released in the form of radiation. d. the electron must be transferred to another atom.

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

Based on its chemical properties, identify the position of each chemical family on the periodic table.

Which statement explains which component is likely to be more powerful in explaining a scientific phenomenon? a) component c, because a theory is often passed on possibility and not certainty b) component d, because a hypothesis is often based on possibility not certainty c) component c, because the ability to explain several occurrences in the natural world is a characteristic of a hypothesis d) component d, because the ability to explain several occurrences in the natural world is a characteristic of a theory