Help her choose words to complete the following statements: A positively charged particle in an atom is a(n) proton
, and a particle with no charge is a(n)
neutron
. These two particles form a dense center called the
nucleus
. Each particle that moves around this center is called a(n)
electron
.

Drag each tile to the correct box. the body monitors the levels of oxygen in the blood to regulate breathing. isabel is running in a marathon and is near the finish line. she feels out of breath. how will her nervous system work to generate a reaction? arrange the tiles in chronological order. isabel's breathing rate increases. sensory receptors in the arteries detect low oxygen levels. the brain sends signals through motor neurons. sensory neurons generate an impulse. the central nervous system relays an impulse to certain brain regions.