Elements in group 17 have similar properties because they all have the name number of what

Elements in group 17 have similar properties because they all the same number of electrons and valence electrons.

The atoms of the elements in Group 17 (also called the halogens) have seven electrons in their highest occupied energy level (the outer shell). This is why their chemical properties are similar.

Explanation:

They all form acids when combined with hydrogen.

They are all fairly toxic.

They readily combine with metals to form salts.

They have seven valence electrons in their outer shell.

They are highly reactive and electronegative.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

b is the correct answer

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