The Ancient Egyptians used simple sundials and divided days into smaller parts, and it has been suggested that as early as 1,500BC, they divided the interval between sunrise and sunset into 12 parts. ... Known as a clepsydra, it uses a flow of water to measure time.
Frequency can effect how tall or how long these Wavelengths are and their strength, therefore how "frequently" they will complete a wave-cycle.
2. F is non-metal, because it has seven electrons (more that 3)
3.It <span>fills its shell by gaining one electron, because it is easier to gain 1 e⁻ than to loose 7 e⁻.
4. It </span><span>becomes a negatively charged ion, because atom of F is neutral, it has "0" charge, and it takes one negatively charged electron(-1). (0 +(-1)= -1)</span>
4 sig fig in that expression
Answer : Option A) Atomic number of Arsenic is 33.
Explanation : Arsenic contains same number of protons in its atomic nucleus. In arsenic there are 33 protons found in the atomic nucleus. Hence, the atomic number will be 33. It has 5 valence electrons in its outermost shell, which is also called as valence shell. So, its valency becomes 5.
