The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three. The hydrogen bonding between complementary bases holds the two strands of DNA together.
A layer of greenhouse gases – primarily water vapor, and including much smaller amounts of carbon dioxide, methane and nitrous oxide – acts as a thermal blanket for the Earth, absorbing heat and warming the surface to a life-supporting average of 59 degrees Fahrenheit (15 degrees Celsius).
Hearing loss due to sound energy damaging the nerve cells in the inner ear. Many animals behavior is influenced by sound energy. They learn to associate events with sounds, so they run when something crunches in the dry grass (might be a coyote), but won't be bothered by the sound of a waterfall. Mood is affected by sound energy. A wine glass can break with sound energy, if the frequency matches the resonant frequency of the wine glass and the amplitude is great enough (one Mythbusters show featured a professional singer who broke a wine glass with his voice without any amplification).
Explanation:
Metals tend to have 1-3 valence electrons in their outer shell, while non metals have 4-8 electrons in their outer shell. Metals are natural elements that are hard, opaque, shiny and dense. While non metals are chemical substances that are soft, transparent, non-shiny and brittle. You can also distinguish a metal from a non-metal based on its appearance: metals are Lustrous while non metals are Non-lustrous. In other words metals are shiny while non metals are usually dull or simply "not shiny". Melting and Boiling point can also help distinguish between metals and non metals: metals tend to have : very high melting and boiling point. Nonmetals have Low melting and boiling point. Metals are also good conductors of heat and electricity, while nonmetals are poor conductor of heat and electricity. And lastly, metals are malleable and are always hard except for sodium, and nonmetals are non-malleable and are soft except for diamonds.
