Which property of argon makes it useful for potassium-argon dating?

It decays into potassium.
It is an unstable element.
It remains trapped in rock.
It is useful only for dating newer roc

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.