Astatine is placed in group-17 in the Periodic Table. Its symbol is At.
Compounds are not placed in the periodic table.
If new elements are placed, then they would be appended in the periodic table. It won't disturb existing periodic table.
CO3 is not placed in periodic table. Only elements are arranged in periodic table.
Metals are placed at the left. Non-metals are placed at right in periodic table.
The abbreviation for potassium is " K " in the periodic table. It is placed in group-1 of the periodic table.
All chemical elements are placed in the periodic table.
Periods are placed horizontally in the periodic table of Mendeleev.
After lanthanum, thus the name.
No. Xenon is not the first period of the periodic table. It is placed in the 5th period of periodic table.
Lanthanides are placed in a special row under the classical periodic table; but this arrangement is only a convention.
Acids are not on the periodic table. Acids are compounds, the periodic table is only for elements.