The decay of 40k has a half of 1.3 × 109 years. the age of the earth is estimated at 4.6 × 109 years. the decay of 40k is a major heat source for the earth's interior. relative to today, how much more heat was produced by 40k in the early archaeon era or 3.9 × 109 years ago?

Astudent made the lewis dot diagram of a compound shown. what is the error in the lewis dot diagram? a)an o atom should transfer all of its six electrons to mg because the formula is mgo b) both electrons of mg should be transferred to one o adam because the formula is mgo c) the electrons should be transferred from each o add him to capital mg because mg has fewer electrons d) the number of dots around mg should be four because it has to transfer two electrons to each o

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

Which explanation is true about what happens to a ray of light when it strikes a mirror? a. a light ray is transmitted toward a mirror at a certain angle. the light ray is then reflected by the mirror at an equal angle but in the opposite direction of the transmitted ray. b. an incident ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then reflected at an angle equal to the angle of incidence but on the opposite side of the perpendicular line. c. a reflecting ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then refracted at an angle equal to the angle of the reflecting ray and on the same side of the perpendicular line. d. an incident ray strikes a mirror at an angle with a line parallel to the mirror. the light ray is then transmitted at an angle equal to the angle of incidence but on the opposite side of the parallel line. you so much! : -d take the time to try and answer correctly.