Which invention has done the most to predict weather and warn people of approaching storms?

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

Identify the electromagnets with poles that are reversed from the electromagnet shown above

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.