Answer:
Most spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as the bulge. ... The spiral arms are sites of ongoing star formation and are brighter than the surrounding disc because of the young, hot OB stars that inhabit them.
Explanation:
<em><u>Voltaic cells convert chemical energy to electrical energy by means of an oxidation-reduction reaction. Electrolytic cells convert electrical energy to chemical energy, so they are the opposite of voltaic cells. ... This is because the sites of oxidation (the anode) and reduction (the cathode) are switched.</u></em>
Answer:
50km
Explanation:
70km - 20km = 50 kilometers
Electromagnetism
Theoretically it is a branch of physics that contains two sources. Either electrically charged particles or the behavior between Neutrons and protons etc.
Answer: The oxygen atom in a water molecule carries a negative electrical charge.
Explanation:
A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Hydrogen bonding (H-bonding) is an intermolecular force having partial ionic-covalent character. H-bonding takes place between a hydrogen atom (attached with an electronegative atom e.g. O, N and F) and an electronegative atom (O,N and F).
In , , O is a highly electronegative atom attached to a H atom through a covalent bond. Therefore O atom gets partial negative charge and H atoms get partial positive charge.