Which phrase refers to the repeating pattern of a minerals particles A solid structure
B crystal structure
C organic structure
D inorganic structure

Florian discovers a rock that is broken into pieces. each piece has several bands. which type of rock does florian predict these pieces will change into when subjected to heat and pressure? igneous magma metamorphic sedimentary

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?