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boron has an atomic mass of 10.810 amu consists of two isotopes.
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(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
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In 1851 gold-seekers from around the world began pouring into the colonies, changing the course of Australian history. The gold rushes greatly expanded Australia's population, boosted its economy, and led to the emergence of a new national identity.
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Answer:
The movement of the electron changes the amplitude of the wave. The farther the electron moves from the center position, the greater the amplitude.
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