Aheliocentric model of the earth was first proposed by: issac newton tycho brahe johannes kepler nicolaus copernicus

Which compound contain an iron with a 3+ charge

Light waves travel than sound waves.

The chemical equation below shows the reaction of sodium (na) and chlorine (cl) to form sodium chloride (nacl). 2na + cl2 → 2nacl in this equation, which of the following is a reactant? i. sodium ii. chlorine iii. sodium chloride