The periodic table was createdby grouping elements according to their properties. Oxygen is a gas that has 6 valence electrons and is colorless. Which of the following unknown element would be grouped along with it? A. Boron B. Selenium C. Aliminum D. Phosphorou

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

The term equestrian relates to which animal? bulls cows horses pigs

Which of the following two events occur to create a sea breeze? select all that apply. warm air rises on the ocean and moves toward the land to cool warm air rises on land and moves toward the ocean to cool cool air moves from the ocean to be warmed by the land cool air moves from the land to be warmed by the ocean