I dont get this help me ( this is science but theres no tab)

Ted and emily played a mixed doubles tennis match against jack and brenda. in the second match. ted and brenda played against jack and emily. which type of chemical reaction does the situation demonstrate?

How many valence electrons are in atom of radon?

An unsaturated hydrocarbon is a hydrogen-carbon compound with a. a network solid structure b. single bonds c. single bonds in a branched-chain structure d. double or triple bonds