19) According to the Heisenberg Uncertainty Principle A) an electron can never appear in the exact same position twice. B) electrons must always absorb energy when moving to higher quantum levels. C) s orbitals are spherical in nature. D) you cannot accurately know both the position and momentum of an electron at the same time.

D

Explanation:

Heisenberg’s uncertainty principle in quantum physics by German physicist Werner Heisenberg in 1927 states that the more accurately the velocity of an object (electron) is determined , the less accurate the position of the object is known and vice versa. The principle talks about how difficult it is to determine the precision of two related parameters.

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

massxgravity x heght=weightxheight= pe

4900=490xh

h=10