Least dense means the one that is at the top. Wood floats on top of water, so wood would be the least dense. Water has a density of 1 and the others would all sink, so they're more dense. The answer is wood
<span>the noble gases are those who occupy the eighth group of the periodic table and are so called because having the complete valence shell do not need to form bonds with other atoms and are thus in atomic form ...
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The noble gases (also called rare gases) are of the inert gases that constitute the eighteenth [1] group of the periodic table of the elements, ie, the right-most column. They consist of atoms with electron shells full. It includes the following elements: helium neon argon krypton xenon radon Ununoctium <span>Sometimes they (particularly helium) are located together with other gases (mostly nitrogen and methane) into endogenous sources; helium of endogenous origin comes from the decomposition of radioactive elements present in the subsurface that emit α particles (ie ions He2 +): These oxidized species present in the soil and become elio.I atoms of the noble gases are all monatomic gas, not easily liquefiable, present the atmosphere in different percentages; the most common is argon which is approximately the 0.932%.</span>
Answer:Light bounces off of the mirror and then appears to come from behind the mirror.
Explanation:Plane mirrors form images that are virtual, upright and the same size and shape as the object it is reflecting.
When rays of light from the object hits a plane mirror they bounces off the mirror,that is they undergo reflection, and appear to originate from behind the mirror, resulting to the formation of a virtual image.
The image formed appears to be behind the plane in which the mirror lies. A virtual image is an image that is formed at a location from which the rays of light appear to come from. The image can not be formed on a screen..
Diffusion is the process of a substance spreading out to evenly fill its container or environment. Kinetic energy of particles of matter increases with an increase in temperature. More the kinetic energy in the particles, more is the rate of diffusion. so diffusion is faster in the summer!
hope this helps!
Carbon-14 is radioactive isotope of carbon.
Carbon is essential element of living cells. While the living cells are alive, the carbon contained in them are in equilibrium with the carbon in atmosphere. But, once the cell dies, the carbon-14 isotope undergoes radioactive decay. By measuring the carbon-14 in atmosphere to the carbon-14 in dead organism, we can calculate the time (or years) that organism have died.
However, carbon-14 dating technique is not accurate for estimating the age of materials older than 50,000 years old (above 40,000 years). This is because, 99% of carbon is carbon-12, 1% is carbon-13 and trace remaining is the carbon-14. This means, carbon-14 is found in very trace amount, in fact 1 part per trillion of carbon atoms present is carbon-14. The half of life of carbon-14 is 5,730 years. For dating the organism, we use the concept of half lives of the carbon-14 isotope in the dead organisms and calculate how many half life old the sample is. But as the years increases, the number of carbon-14 isotope becomes too low to detect and make accurate calculation.
This means, at some point the organism can simply run out of carbon-14.
Hence carbon-14 dating is not accurate for estimating age of materials older than 50,000 years old.
