Answer:
Mendeleev had left the noble gases out of his periodic table.
Explanation:
Mendeleev's periodic table is pictured in the image attached to the question.
Mendeleev's table obviously lacked the noble gases. The reason for this grave omission is simple; the noble gases were not known as at the time when he formulated his periodic table. There weren't any known elements whose properties were similar to the properties of the noble gases. This would have lead him to suspect their existence.
Foods are a solid we need to survive
Im pretty sure the answer is 4 but not 100 percent
Silicon must have 4 single covalent bond, every single bond has 2 electrons (one pair), so 4·2=8 electrons (octet).
1. A filter was used to separate the sand from the salt water solution (The process of decanting was used if a filer was not available).
2. A Bunsen burner was used to boil away the water from the salt water solution leaving only salt.
I hope this helps. Let me know if anything is unclear.
