A rock sample contains 25 percent k-40 and 75 percent daughter product ar-40. if k-40 has a half-life of 1.3 billion years, how old is the rock?

The instructions for the genetic traits of an organism are directly determined by the a-numbers of a,t,c and g units in a sugar molecule b-sequence of the bases in dna molecules c-length of a dna molecules d-way the bases are paired in the two strands of a dna molecule

Apart of the periodic table is shown. a portion of the sixteenth and seventeenth columns of the periodic table is shown. column 16 reads eight oxygen, 16 sulfur, and 34 selenium. column 17 reads nine flourine, 17 chlorine, and 35 bromine. which of the following elements is less reactive than the others? bromine (br) oxygen (o) selenium (se) sulfur (s)

Which table best shows the impacts resulting from human activity? impact of human activities human activity impact forest area cleared to construct an airport increase in oxygen level vegetation cleared to construct an oil mine increase in pollution impact of human activities human activity impact forest area cleared to construct an airport increase in sound pollution vegetation cleared to construct a power plant contamination of water impact of human activities human activity impact beehives cleared from urban areas increase in vegetation dams constructed on a river increase in fish population impact of human activities human activity impact beehives cleared from urban areas increase in bird population dams constructed on a river better quality of water