Which two observations below can be evidence that a chemical change has occurred

A. Production of bubbles (a gas)

B. melting

C. vaporization

D. production of heat

According to Hund's rule, when electrons occupy orbitals of equal energy, one electron enters each orbit until A. there are two electrons in each orbital. B. electron velocities become constant. C.

Now do the same computation for all six pairs of values. What is the average of all six fractions V/ T?

Mendeleev devised his periodic table by ordering the elements according to their atomic number. TRUE OR FALSE

How could you seperate a mixture of sand and sugar?

If an atom donates or accepts an electron, what is it considered

Where are two places that scientists obtain scientific knowledge

Which of the following best describes what happens when an ionic bond forms? A) two atoms come together and share electrons in order to fill their octets. B) two atoms give up their electrons in order to form a bond.

Describe the attraction between 2 atoms as a result of sharing electrons

I need to know about mitosis and meiosis

What is sediment and debris, and what role does it play in the way sedimentary rock forms?