Students are given a solid sample and asked to determine whether the sample is an element, compound, or mixture. One student observes that the sample is: made up of particles of different colors, sizes, and shapes
some particles are softer than others
some shine while others appear dull
What can the students conclude about their sample?

It is an element.

It is a compound.

It is a homogeneous mixture.

It is a heterogeneous mixture.

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

Convert the temperature of dry ice, –77 ∞c, into degrees fahrenheit and kelvin.

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.