Answer:
A.
Explanation:
zinc and hydrochloric acid reacts to form zinc chloride and hydrogen.
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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.
Answer:
electron cloud charge of manganese=-5
Explanation:
atomic number=number of elecron +neutron number
DATA
Neutron NO.=30
atomic NO.=25
e=?
A=e+n
25=e+30
e=25-30
e= -5
Answer:
c. Boundary where air masses meet and cold air rises above warm air.
Explanation: