The
two categories that are used to classify physical changes are Reversible and
Irreversible.
Reversible
means that the matter can convert to gas, liquid and solid and then convert
back to gas, liquid or solid. So it means it can convert back and forth.
<span>Irreversible
means that matter cannot be converted back as it is before.</span>
Answer:
through
space at the speed of light. Sometimes astronomers will use two
telescopes on opposites sides of a planet and combine the image from
each telescope. When combined, the two telescopes act like one giant
telescope and have the ability to reveal important details from space. If
astronomers are detecting electromagnetic waves with a wavelength of
109, what type of wave are they detecting?*
Explanation:
NICE
Answer: some energy is lost from the pyramid, energy is transferred from bottom (producers) to top, but in decreasing amounts.
Explanation: total energy is conserved, but not necessarily within the energy pyramid, which is an open system where energy is lost from the pyramid, mainly as heat but also as sound.
Energy is transferred up the pyramid but the amount transferred at each stage is less because of losses outside the pyramid.
Answer:
yes, gold can be created from other elements. The process requires nuclear reactions and is so expensive that currently it would cost a lot more than the price of natural gold available, therefore, unprofitable. Gold is the chemical element with 79 protons in each atomic nucleus. Every atom containing 79 protons is a gold atom, and all gold atoms behave the same chemically. In principle, gold can be created by simply assembling 79 protons, (and enough neutrons to make the nucleus stable).
Answer:
B
Explanation:
Viruses don't have cell walls that can be attacked by antibiotics; instead they are surrounded by a protective protein coat. Unlike bacteria, which attack your body's cells from the outside, viruses actually move into, live in and make copies of themselves in your body's cells.
