Answer:
Helium is in group 18 of the periodic table. How is helium different from the other elements in this group? = Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
An emission spectrum will occur when = An electron releases energy and falls back to a lower energy level.
Explanation:
An increase in the atmospheric concentrations of greenhouse gases produces a positive climate forcing, or warming effect. From 1990 to 2015, the total warming effect from greenhouse gases added by humans to the Earth's atmosphere increased by 37 percent.
The B. Ca-F pair has the greatest electronegativity difference.
Electronegativities <em>increase from the lower left to the upper right</em> in the Periodic Table.
Ca is closest to the lower left, and F is in the upper right, so the Ca-F bond has the greatest electronegativity difference.
Answer:
When metals react they lose electrons.
Explanation:
An ion is defined as a molecule or atom made up of a different number of electrons and protons. This makes the electric charge of the molecule net, not neutral.
In other words, an ion is a molecule or atom that has a positive or negative electric charge, making it an atom whose electric charge is not neutral.
The characteristic property of a metallic atom is to lose one or more of its electrons to form a positive ion. That is, metals lose electrons and acquire a net positive charge, which is why they are electropositive.