All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.
In a) the final equation is AgNO3 + KCl = AgCl + KNO3, b) Ni(NO3)2 + Na2S = 2NaNO3 + NiS; c) CaCl2 + Na2CO3 = 2 NaCl + CaCO3. In 2) The total net equation is Ca 2+ + CO32- = CaCO3 (s).
Answer:
The arrangement of the periodic table leads us to visualize certain trends among the atoms.
Elements are arranged from left to right and top to bottom in order of increasing atomic number.
The vertical columns (groups) of the periodic table are arranged so that all its elements have the same number of valence electrons (outer ring). All elements within a certain group share similar properties.
The rows are called periods. All elements in a row have the same number of electron shells.
Carbon is the only element that can form so many different compounds because each carbon atom can form four chemical bonds to other atoms, and because the carbon atom is just the right, small size to fit in comfortably as parts of very large molecules.
