Calcium has an atomic number of 20; therefore, calcium has 20

protons

protons plus neutrons

shells

How do the circulatory and respiratory system interact to provide muscle cells with oxygen during a long distance race?

What actually forms code found in DNA?

What is a signal to which an organism responds

The energy pyramid shows the flow of energy through a temperate forest ecosystem. Which trophic level has approximately 100 times more energy than the apex consumer level? A. Apex Consumers B. Tertiary Consumers C. Secondary Consumers D.

If you were in a boat as Hurricane Sandy passed overhead on October 28 at 4am, at what altitude would Polaris appear in the sky from your location (32°N and 73°W) ?

The major body structures and organ systems form during which trimester

What is the main female sex hormone? is it d? testosterone adrenaline insulin estrogen

What kind of a Erosion involves dissolved particles

Based on family pedigree studies, which relative of an individual with a diagnosis of schizophrenia would be most at risk for developing the disorder?

Which tools do meteorologists use to collect data about the weather? Check all that apply. satellites weather fronts maps and charts weather balloons automated weather stations