1. Marie put a 4 centimeter (cm) square block of foam in a bucket of water and it floated. Why did it float?
A. The foam is less dense than the water.
B. The foam has air bubbles which make it float.
C. The foam is smaller than the bucket of water.
D. The foam weighs less than all the water in the bucket.

i believe the answer is 5,000

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.