Which electron configuration represents an
excited state for a potassium atom?
(1) 2-8-7-1 (3) 2-8-8-1
(2) 2-8-7-2 (4) 2-8-8-2

In an oxidation-reduction reaction, oxidation is what happens when a reactant

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

Which are examples of how technology has advanced scientific understanding.1using hot water to sterilize medical equipment.2transplanting a human organ into another individual.3inserting genes from one sheep into another cell to make a cloneunderstanding the different structures that make up a cell.4examining microorganisms from the deepest parts of the ocean