In studying chemistry, one should learn how to read the periodic table and periodic trends in the table.. Of course, you should also know the abbreviations of each element in it so that you can identify what element is in chemical structures. Memorizing and knowing it by heart is the best way. You should also study what we call chemical nomenclature which is naming combinations of elements. Elements when combined may form ionic compounds, bonds or acids. Knowing what element reacts with another will also be necessary that's why the concept of chemical reactions must be further studied.
Answer:
.
Explanation:
Based on the electron configuration of this ion, count the number of electrons in this ion in total:
.
Each electron has a charge of 
.
Atoms are neutral and have 
charge. However, when an atom gains one extra electron, it becomes an ion with a charge of . Likewise, when that ion gains another electron, the charge on this ion would become 
.
The ion in this question has a charge of . In other words, this ion is formed after its corresponding atom gains two extra electrons. This ion has 
electrons in total. Therefore, the atom would have initially contained 
electrons. The atomic number of this atom would be 
.
Refer to a modern copy of the periodic table. The element with an atomic number of is sulphur with atomic symbol 
. To denote the ion, place the charge written backwards ("
" for a charge of ) as the superscript of the atomic symbol:
.
Explanation:
Atomic Number = Number of protons
Mass Number = Number of protons + Number of neutrons
Isotopes are simply atoms of an element with the same number of protons and different number of neutrons.
First Isotope -- 238U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 238 - 92 = 146
Second Isotope -- 235U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 235 - 92 = 143
Answer:
1 kiloliter = 1,000,000 milliliters
45 × 1,000,000
45 KL = 45,000,000 ML
