Explain how you can determine if a chemical reaction a single replacement reaction or a double replacement reaction

Need asap ‼️ 20 pts which gravitational force field diagram is drawn correctly? (answers in pictures below)

Scientist have use computer models to create a series of maps that show how susceptible coastal cities in island countries are to the sea rising at different levels.the map shows that a 1 meter rise would swap cities all along the us eastern seaboard. a 6-meter sea level rise with sub merge a large part of florida. thermal expansion has already raise the oceans 10 to 20 centimeters the most likely cause,directly and indirectly, for such a rise in sea level is

How do you know how many valence electrons an atom has?