Elizabeth was studying the history of the cell theory and the contributions of different scientists. She made this table to compare two of the scientists.

X
Y
observed objects using a microscope observed small organisms using his own version of a microscope
called what he observed "cells” called what he observed "animalcules”
Which pair of scientists should Elizabeth write instead of X and Y?

The reactions of photosynthesis occur in the of plant cell? a. mitochondria. b. lysosomes. c. chloroplasts. d. chlorophyll

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy

Calculate the estimated density of each ball. use the formula d = m/v where d is the density, m is the mass, and v is the volume. record your calculations in table a of your student guide. given that the density of water is 1.0 g/cm3, make a prediction about whether each ball will float in water. record your prediction in table a. what is the estimated density of the table tennis ball? record your answer to the nearest hundredth