Answer:
Three chemical elements: hydrogen, oxygen, and helium.
The difference between metals and metalloids is: metalloids have properties in between those of the metals and non-metals and are semiconductors.
The periodic table is organized by the elemts atomic number, it goes from the element with the lowest atomic number (which is hydrogen) to the element with the highest atomic number (oganesson)
Explanation:
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Answer:
water, when the metastable state is reached, is cooled below the zero temperature. It freezes abruptly. this is called metastable. They are not at equilibrium per se; as at negative temperatures the only equilibrium state of water is ice.
Explanation:
Answer: The correct option is A.
Explanation: The given molecules are the molecules of same element.
These molecules are considered as diatomic species.
Polar molecules are the molecules in which some polarity is present in the bond. These molecules are formed when there is some difference in the electronegativities of the elements. Example: HCl
Non-polar molecules are the molecules where no polarity is present in the bond. These molecules are formed when there is no difference in the electronegativities of the elements. Example: 
The given molecules are non-polar in nature.
Hence, these molecules must be non-polar. So, the correct option is A.