1 valence electron in alkali metals.
The periodic table is one of the most important tools in the history of chemistry. It describes the atomic properties of every known chemical element in a concise format, including the atomic number, atomic mass and relationships between the elements. Elements with similar chemical properties are arranged in columns in the periodic table.
The table thus is a quick reference as to what elements may behave the same chemically or which may have similar weights or atomic structures.
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The equation that relates both energy and wavelength is:

where e is the energy and lambda is the wavelength.
Therefore, as we can see from this equation, the energy of an electromagnetic wave is inversely related to the wavelength of the electromagnetic wave.
Its what the formula of a coupon between PB to plus plus to
Answer:
Element
Explanation:
An element is substance that is composed of only one kind of atom and can not be separated into simpler substances or converted into another substance by chemical processes.
Chemical elements are found in the periodic table. Examples of chemical elements include; sodium potassium, phosphorus, hydrogen etc.