. If a substance has an excess number of electrons on its surface, what type of charge does it have?
A positive charge.

A negative charge.

A neutral charge.

A nuclear charge.

A negative charge

Explanation:

If there is an excess of electrons in a substance, this will have a negative net charge. This is because electrons have negative charge

q = -1.67*10^{-19}

each electron will contribute with this charge to the total negative net charge of the substance.

hence, the answer is "A negative charge"

explanation:

could i give you a exaplo that could you?

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.