Respiration removes oxygen from the atmosphere, and photosynthesis puts oxygen into the atmosphere.
d= 8/10 so yah that was a guess
Metals are located on the left of the periodic table, and nonmetals are located on the upper right.
Explanation: Metals: Lustrous (shiny)
Good conductors of heat and electricity.
High melting point.
High density (heavy for their size)
Malleable (can be hammered)
Ductile (can be drawn into wires)
Usually solid at room temperature (an exception is mercury)
Opaque as a thin sheet (can't see through metals)
Nonmetals: High ionization energies.
High electronegativities.
Poor thermal conductors.
Poor electrical conductors.
Brittle solids—not malleable or ductile.
Little or no metallic luster.
Gain electrons easily.
Dull, not metallic-shiny, although they may be colorful
<span>When an atom or compound is oxidized, its properties change. For example, when an iron object undergoes oxidation, it is transformed because it has lost electrons. Unoxidized iron is a strong, structurally sound metal, while oxidized iron is a brittle, reddish powder. The diagram below illustrates what happens to an atom of iron as it is oxidized
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<u>Halogens are reactive because:</u>
They have high electronegativity and also high nuclear charge. So, they are reactive and also gain an electron when they react with other elements.
Since they are very reactive, halogens are very harmful to living organisms. Some of the halogens are fluorine, chlorine, bromine, iodine, astatine. These are mostly non metals. Fluorine is one of the most reactive gas and also very toxic gas. When Fluorine reacts with glass along with small amounts of water, it forms silicon tetra fluoride (SiF4). Hence fluorine should be handled with substances like the inert organofluorine compound Teflon.
