Photoelectrons are removed with kinetic energy 1.864×10^-21 j, when photons of light with energy 4.23×10^-19 j fall on the metal. what is the minimum energy required per mole to remove an electron from potassium metal?

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?

Juju.01) 5 geologic events a group of students designed an experiment in an ice rink to represent the solar system. the steps of the experiment are listed below. 5: geologic events 1. choose a student to represent the sun. the planets are represented by two tennis balls. 2. ask the student to hold the tennis balls in each palm and spin on the ice with arms stretched out. 3. ask the student to draw in the arms after about 10 spins. 4. observe the student's arms rotate faster when they are closer to the body. 05 geologic events enors) the experiment most likely demonstrates that (2 points) 07 discussion-based sessment/module planets exert gravitational force on the sun the sun exerts gravitational force on the planets 3.07 discussion-based ssessment speed of a planet depends on its distance from the sun new version available! (3.0.119) get it now submit 18.07: module exam description

Which radioisotope is used to date fossils? a. oxygen-16 b. carbon-14 c. uranium-238 d. carbon-12