Answer:
The circulatory system, also known as the cardiovascular system, is a simple loop which starts, and ends, with your heart. It is a closed system, meaning blood does not enter or leave the system during its journey from your heart to your body and back again.
Explanation:
Answer:
valence electrons
horizontal row on the periodic table
cation
anion
solid, ?
high
electricity
cation first, then anion
low
they do not conduct electricity
halogens
a representation or simulation for device structure, process equipment, or a management system ?
atom
protons and neutrons (and electrons?)
elements are arranged from left to right and top to bottom in order of increasing atomic number
Explanation: