Answer:
Fluorine > Selenium > Arsenic > Potassium > Argon
Explanation:
Electron affinity describes the ability or readiness or tendency of an atom to gain an electron.
The higher the value, the higher the tendency. Electron affinity depends on the on the nuclear charge and atomic radius. When nuclear charge is more, electron affinity is high, when atomic radius increases electron affinity reduces.
Noble gases such as Helium, Neon, and Argon would have 0 affinity for electrons because of their stable electronic configuration. From the list, Ar is the least in terms of electron affinity.
Potassium is a metal with large electropositivity which describes the tendency of an atom to lose electrons. Potassium would readily lose electrons instead of gaining.
Between Arsenic and Selenium: Arsenic belongs to group V and Selenium group VI. The two elements both belong to period IV on the periodic table. Across a period, electron affinity increases due to increase in nuclear charge. Therefore, Selenium would have a greater electron affinity compared to Arsenic.
Fluorine has the highest electron affinity of all. It needs just an electron to complete its octet.
Answer: A convex lens is used to converge ligtht.
Explanation:
A concave lens is a lens that is thicker on the ends than in the middle. As consequence of this, a concave lens diverges (separate) the rays of light. A concave lens is also called diverging lens.
A convex lens is is thicker in the middle than on the ends. As consequence of this, a convex lense converge the parallel rays that pass through it. A convex lens is also called converging lens.
The ion is Al³⁺
mass number - number of neutrons= atomic number
27 - 14 = 13
Aluminum has an atomic number of 13, thus we know this is the metal in question. Also, because the aluminum has only 10 electrons, (3 less than a neutral atom of aluminum would have), its charge must be 3+
