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Answer:
physical
Explanation:
The zinc (which was already silver) coated the penny. The NaOH dissolved the zinc. (that was what made the water murky) And small pieces of zinc adhered to the penny (coated) It was a physical change because no NEW color was created.
The valence electron does the halogens possess are 7
- Valence electrons are found in the outermost energy level of an atom
- They are involved in the formation of chemical bonding with other atoms.
- The halogens elements are found in group 17 on the periodic table
- The halogens include fluorine, chlorine, bromine, iodine and astatine.
- They have seven valence electrons, so they are extremely reactive as they only need one more to fill their outer shell.
- By octet rule we can say that the electron with 8 outer most shell is full and stable.
Hence the halogens posses 7 valence electron
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