The 54.9-g sample of the compound X2O7 contains 33.6 g of oxygen atoms. What is the molar mass of element X?

Theoretically, which nonmetal should be the most reactive? He Rn F At

The hydrogen atomic emission spectrum includes a UV line with a wavelength of 92.3 nm. Is this line associated with a transition between different excited states or between an excited state and the ground state?

What gas is produced by the re baking soda? a. oxygen B. petroleum С. helium D. Carbon dioxide

Use the dot structure on the right and the Periodic Table to determine the element represented. sodium (Na) potassium (K) neon (Ne) argon (Ar)

Given the law of conservation of energy, what happens when a 200°C iron bar is placed in thermal contact with a 30°C block of wood? A. Energy leaves the iron bar and enters the wood until the temperatures are equal. B.

Which of the following is easist to accelerate? A. bowling ball B. tennis ball C. golf ball D. ping pong ball

Fish need at least 4 ppm dissolved o2 for survival. part a what is this concentration in mol/l?

How does a runoff get polluted.

Anatom that has lewer neutrons than protons and more electrons than protons is

Which can have either a positive charge or a negative charge when they are released during radioactive decay? A. alpha particles B. beta particles C. positrons D. photons