Valance electrons are the extra electrons on the outermost orbital, that hasn't been filled yet. For example, Lithium would have one valence electron, on the 2s orbital, because that is an extra electron floating around that 2s orbital, that can be shared with others, since each element's goal is to have no valence electrons. If an orbital is filled, it therefore has no valence electrons, because valence electrons are only extra electrons, if that makes any sense.
There are many groups of the periodic table. These groups categorize electrons by the amount of valence electrons they have. The group on the far left, the alkali metals, all have one valence electrons. The alkali metals include Lithium, Sodium, and other elements, so therefore give away that one electron easily, because if they give it away they won't have any valence electrons. (This is why you often see salt, sodium chloride, because sodium gives away its one valence electron to chloride, who needs one electron to have no valence electrons.) One other notable group is the noble gases, on the far right of the periodic table. These elements have no valence electrons, so therefore won't bond easily with other elements.
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The cladogram of the kingdom Animalia shows the relationship of selected animals based on their shared anatomical features. The black numbered squares represent features that are critical for forming each branch in the animal kingdom. Square one represents a dorsal nerve cord, which means the animals in all the branches have a dorsal nerve cord.
Which numbered square would represent the trait "mammary glands
Answer - C. 5
The activity series goes top to bottom, most active to least active elements, going: Li, K, Ba, Sr, Ca, Na, Mg, Mn, Zn, Fe, Cd, Co, Ni, Sn, Pb, H, Cu, Ag, Hg, Au.
Thus, your list of metals would go from most reactive to least reactive: Li, K, Mg, Zn, Fe, Cu, Au
Answer:
we add only the the same highest enegy levels :3s&3p=2+4=6
Answer:Calcium atoms have smaller radii than potassium atoms since calcium atoms have a greater nuclear charge.
Explanation: