The shape of a molecule is tetrahedral. how many lone pairs are most likely on the central atom?

zero
two
three
four

Zero lone pairs on the central atom.

Explanation:

The molecule is with with tetrahedral shape which means that molecule has a tetrahedral geometry.

The value of number of electrons around the central atom with tetrahedral geometry according to VESPR theory is '4'. Which means that electrons around the central atom are 4.

Since, the molecule is in tetrahedral shape which means four bonds are pointing in direction towards the four vertices of tetrahedral which means their are zero lone pair present on the central atom.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e