Galaxies Unit Review Practice The universe's galaxies have evolved since what point in time? (1 point)
O 13.8 billion years ago, right after the universe first formed
O approximately 50 million years ago after initial clumps of material were formed
O 23 4 billion years ago, when the universe first formed
O 800 million years ago, when gas concentrations were optimal for galaxy formation

Motivation cannot be developed with practice; a person either possesses it or they do not.

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

How many miles of water are produced if 5.43 mol pbo2 are consumed