Which element has the same number of valence electrons as bromine (Br)?
(1 point)
Responses
selenium (Se)
selenium (Se)
chlorine (Cl)
chlorine (Cl)
potassium (K)
potassium (K)
krypton (Kr)
chlorine (Cl)
Why are sodium (Na) and potassium (K) in the same group on the periodic table?(1 point)
Responses
They have similar reactivity.
They have similar reactivity.
They have similar atomic weights.
They have similar atomic weights.
They are both hard and brittle.
They are both hard and brittle.
They are both colorless.
They have similar reactivity.
The element that has the same number of valence electrons as bromine (Br) is chlorine (Cl).
To determine the element that has the same number of valence electrons as bromine (Br), we need to look at the periodic table. Valence electrons are the number of electrons in the outermost energy level of an atom.
In this case, bromine (Br) is located in Group 17 (Group VIIA) of the periodic table. Group 17, also known as the halogens, contains elements with 7 valence electrons.
Now, let's go through the options:
- Selenium (Se) is located in Group 16, one group above bromine, and has 6 valence electrons. Therefore, it does not have the same number of valence electrons as bromine.
- Chlorine (Cl) is also located in Group 17, the same group as bromine, and has 7 valence electrons. Chlorine does have the same number of valence electrons as bromine.
- Potassium (K) is located in Group 1, also known as the alkali metals, and has 1 valence electron. Therefore, it does not have the same number of valence electrons as bromine.
- Krypton (Kr) is located in Group 18, also known as the noble gases, and has 8 valence electrons. Therefore, it also does not have the same number of valence electrons as bromine.
Based on this analysis, the element that has the same number of valence electrons as bromine (Br) is chlorine (Cl).