The measure of the first on an object is what

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

One of the main reasons societies settled along rivers in the neolithic era was because a) the village elders demanded it. b) the land there was more valuable. c) it was more safe and secure there. d) it provided irrigation for farming.

Astate's representation in the u.s. senate is based on a) equal representation. b) the state's population. c) the state's electoral votes. d) the size of their major cities.this independent regulatory agency was created in 1974 to oversee and regulate the financing of political campaigns in the united states. a) warren cthis independent regulatory agency was created in 1974 to oversee and regulate the financing of political campaigns in the united states. a) warren commission (wc) b) federal election commission (fec) c) equal opportunity commission (eoc) d) securities and exchange commission (sec)