Which element is present in the compounds for ammonia and baking soda?
a. hydrogen
b. magnesium
c. chlorine
d. carbon

Which set of characteristics best describes igneous rock? a) largest type of rock, made of organic matter, hardest type of rock b) least abundant type of rock, made of other rocks, made mostly of minerals c) found on all continents, contains wavy bands of stripes, contains fossils d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?

What human activity increases beach erosion?