Question

according to the general trend of electronegativity, which of the following elements has the largest electronegativity: li, mg, na, or be?
be
mg
li
na
clear my selection
29
multiple choice 1 point
which of the following families is highly reactive to oxygen and water?
alkaline earth metals
alkali metals
noble gases
halogens
clear my selection

Explanation:

First Question (Electronegativity)

Electronegativity generally increases across a period (left to right) and decreases down a group (top to bottom) in the periodic table. Among Li, Mg, Na, Be: Li and Na are in Group 1 (Na is below Li, so Li > Na in electronegativity). Be and Mg are in Group 2 (Be is above Mg, so Be > Mg). Now compare Li (Group 1, Period 2) and Be (Group 2, Period 2). Since electronegativity increases across a period, Be > Li. So Be has the largest electronegativity.

Alkali metals (Group 1) are highly reactive with oxygen and water. They have one valence electron, so they readily lose it to form cations, reacting vigorously with $O_2$ and $H_2O$. Alkaline earth metals (Group 2) are less reactive than alkali metals. Noble gases are inert. Halogens (Group 17) react with metals but not as vigorously with water/oxygen as alkali metals.

Answer:

Be (the option "Be")

Second Question (Reactivity with Oxygen and Water)