Periodic Table

The halogens are located in Group 17 of the periodic table, also known as Group 7A. This group includes elements such as fluorine, chlorine, bromine, iodine, and astatine. Halogens are highly reactive nonmetals that typically form salts when they react with metals.

Elements in the same column of the periodic table share similar chemical properties due to having the same number of valence electrons. This leads to similarities in reactivity, ability to form compounds, and other characteristic behaviors.

In some reactions, one of the products of the two reactions may be common(means that for example you can get a same product by using two different chemical reaction).

Simplest example ever(given to grade 6 kids) :

-NaOH + HCl ----> NaCl (Salt) + H2O (Stomach inflamation base displacement with stomach acid)

-H2CO3 -----> H2O + CO2 (Hydrogen Carbonate acid decomposes to water and carbon dixide)

You can get water by using both reactions.

(Ofcourse getting water isn't the purpose) :)

Elements in the same period share the same number of electron shells. This means they have similar atomic sizes and properties because they have the same number of electron shells determining their size and behavior.

Potassium is the most reactive of the three metals (potassium, lithium, and sodium). It reacts vigorously with water, producing hydrogen gas and heat. Sodium is less reactive than potassium, while lithium is the least reactive among the three.

Lanthanum and lutetium: lantanides group

Actinium and lawrentium: actinides group

Actually, it's the other way around. Electrons of transition metals fill d-sublevels, while electrons of inner transition metals fill f-sublevels. Inner transition metals are located in the f-block of the periodic table, while transition metals are located in the d-block.

Halogens refer specifically to a group of elements in the periodic table (Fluorine, Chlorine, Bromine, Iodine, Astatine) with distinct properties, rather than elements with mixed metal/non-metal properties. Elements with mixed properties are often referred to as metalloids or semimetals, such as Boron, Silicon, Arsenic, and Antimony.

f-block columns

Alkali Metals belong to group 1 of periodic table. They have one electron in last or valence shell and are highly electropositive and have low value of Ionisation enthalpy. So the removal of last electron to form a cation(positively charged ion) is very easy and needs less energy as compared to other elements. As a result of this Alkali metals are highly reactive and readily form ionic compounds. Due to this they react with other elements or compounds and form ionic compound. Hence, they are found in their compounds and not in free state.

The atomic number increases by one as you move from right to left across the periodic table. The atomic number represents the number of protons in an atom's nucleus, which increases as you move towards the right due to the addition of more protons in the elements.

Phosphorus has two valencies 3 and 5.

3 - in compounds such as PH3, PCl3, P4O6

5 - PCl5, P4O10

In terms of cordination, the "count" of all the atoms around a P atom it can have 2- 9 atoms around it. Examples are below:-

2 - in OPCH2

3 - in PH3

4 - in PO43-

5 - in PF5

6 - in PF6-

And in some phosphides where there bond is more ionic even higher coordination numbers are known:-

7 - in crystals of Ta2P

8 - in crystals of Hf2P

9 - Ti3P

A relatively small percentage of elements are found in significant amounts in Earth's biosphere, lithosphere, hydrosphere, and atmosphere compared to the total number of elements listed on the periodic table. This is because only a subset of elements are abundant and play critical roles in Earth's systems, with elements like oxygen, carbon, hydrogen, nitrogen, and calcium being among the most prevalent. The remaining elements are typically present in trace amounts or are not as important in the composition of these spheres.

The nonmetals with atomic numbers that are multiples of five are boron (atomic number 5), nitrogen (atomic number 7), phosphorus (atomic number 15), arsenic (atomic number 33), and iodine (atomic number 53).

It is number 47, located in period 5, group 11.

The answer is Carbon

Iron has it's roots in the Proto-Indo-European *h₁ésh₂r̥ meaning "blood", so named because of it's tendency toward a red color when smelted and due to rusting. It's chemical symbol Fe comes from it's Latin name ferrum.

Radon (86). And all the halogens are "non metals".

If there is only one atom, there will not be a number. Otherwise, they are the numbers which are normally written in subscript after the symbol for the element.

Elements in group 15 (or group 5) are non-metals. Thus, elements in group 1 lose electrons, forming positively charged cations, which are gained by elements in group 5, forming negatively charged anions. The attraction between anions and cations is known as an ionic bond.

Example, the reaction between sodium and nitrogen:

2 Na(s) + 3 N2(g) --> 2 Na3N(s)

The formula is due to sodium having a valency of 1 and nitrogen having a valency of 3. These 'cross over' producing the symbolic formula Na3N.

Arsenic did not create the first periodic table. The first periodic table was created by Dmitri Mendeleev, a Russian chemist, in the 1860s.

Other scientists had organized elements in other ways prior to the invention of Mendeleev's periodic table, but the other methods were criticized and did not catch on.

"Ne" on the periodic table stands for Neon. Neon is a noble gas with the atomic number 10. It is colorless, odorless, and tasteless, commonly used in neon signs due to its bright and distinctive red-orange glow when electrified.

"Electronegativity"

Uuo was the temporary symbol give to the element with atomic number 118 which was first produced by scientists at the Joint Institute for Nuclear Research in Dubna, Russia. The temporary symbol represented its name which was ununoctium which, in Latin, stands for "1-1-8". In November 2016, the International Union of Pure and Applied Chemistry (IUPAC) approved the name oganesson for this element.