UN CATIÓN MONOVALENTE POSEE 54 ELECTRONES, ¿CUÁL ES SU NÚMERO
ATÓMICO?

What is the molar mass of babr2? a. 217.2 g/mol b. 297.1 g/mol c. 354.5 g/mol d. 434.4 g/mol

The rock in a lead ore deposit contains 89 % pbs by mass. how many kilograms of the rock must be processed to obtain 1.5 kg of pb?

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.