Write the name and the symbol of the element that fits each of the following descriptions: a) the alkaline earth metal in the sixth period. b) the metalloid in the third period. c) the nonmetal in group IVA. d) the halogen that is liquid at room temperature. e) the group-VIIIB transition metal with properties similar to Ru. f) the third-period element that exists as diatomic molecule.

Astudent made the lewis dot diagram of a compound shown. what is the error in the lewis dot diagram? a)an o atom should transfer all of its six electrons to mg because the formula is mgo b) both electrons of mg should be transferred to one o adam because the formula is mgo c) the electrons should be transferred from each o add him to capital mg because mg has fewer electrons d) the number of dots around mg should be four because it has to transfer two electrons to each o

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

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.