1. Indicar cuáles de las proposiciones son verdaderas : I. El Cloro (Z = 17) esta en el tercer período II. El Litio (Z = 3) esta en el grupo I A III. El Neón (Z = 10) esta en el grupo II A a) I y II b) I y III c)Sólo III d) II y III e) Sólo II

Three alkali metals in group 1 are a. calcium, strontium, barium b. boron, aluminum, gallium c. sodium, potassium, rubidium d. fluorine, iodine, chlorine

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

Which statement accurately represents the arrangement of electrons in bohr’s atomic model?