Periodic Table

Julius Lothar Meyer played a significant role in the development of the periodic table by independently publishing a periodic table of elements that showed the correlation between atomic volume and atomic weight. His work helped pave the way for the later development of the modern periodic table based on atomic number. Meyer's contribution, along with that of Dmitri Mendeleev, laid the foundation for our current understanding of the organization of elements.

protons and neutrons. This is because the atomic mass of an element is calculated by adding the number of protons and neutrons in the nucleus of an atom. The number of protons determines the element's identity, while the number of neutrons affects its stability.

This is a physical change. The solid is Iodine, which sublimes on heating to form gaseous Iodine. When cooled, it sublimes again to form solid Iodine. Since this change is only the change of physical states, and since there's no change in the chemical structure of Iodine, this is a physical change.

Elements in Families on the periodic table have similarities. Elements in the same family as iron are magnetic. The air force had a tremendous problem. Traditional lubricants were not working under the stresses their new machinery used. All of their lubricants were carbon based. They looked at the next element in the same family on the periodic table. It was silicon. They made a lubricant based on silicon. It worked fine. The first diodes and transistors were made with Germanium. It is an expensive metal to produce. It is on the periodic table right above silicon. This led to a number of experiments and attempts to produce a transistor using silicone. Finally after many tries, it worked. Inexpensive silicon transistors could replace expensive germanium ones. You wrote your question because silicon is below Germanium on the periodic table.

Elements can be distingushed apart by the amount of sub-atomic particles in one atom of that element. Every element has a differemt amount of electrons, so you can count the amount of electrons to identify an element. You can also look at the amount of protons and neutrons in an atom. Every element has a different amount of these, too.

The trend in ionic radius from left to right within a period generally decreases. This is because as you move across a period, the number of protons in the nucleus increases, leading to a stronger attraction for the electrons and causing the outer electron shell to be pulled closer to the nucleus, resulting in a smaller ionic radius.

Actinium (Ac)

Atomic Number: 89

Atomic Weight: 227

Protons: 89

Electrons: 89

Neutrons: 138 -----(227-89=138)

No, the first periodic table of elements was created by the Russian chemist Dmitri Mendeleev in 1869. Mendeleev arranged the elements in order of increasing atomic mass and noticed a periodic pattern in their properties, which led to the development of the modern periodic table.

anions are negatively charged species

anions are not seen on the Periodic Table.

however the elements on the right end of the periodic table (except for noble gases, group 18) have a strong tendency to accept electrons are become anions

When Mendeleev made the table, he found that elements with similar chemical properties formed groups. This is because the pattern of the table reflects the pattern of filling the electron shells. Mendeleev didn't know this, and his achievement is all the greater because he had only his knowledge of the way elements behave to guide him.

he ordered the known elements according to atomic mass, which worked out for the most part, until later another scientist came along and realized it worked out even better if arranged according to atomic number (number of protons)

Yes, it is.

If we look at the electronic configuration of Mn2+ , it is 1s2 2s2 2p6 3s2 3p6 4s0 3d5 . The 3d orbital is half-filled, which is relatively stable. in Mn3+ , there are only 4 electrons in the 3d orbital, which is less stable.

The periodic table include only chemical elements each has a unique atomic number that represents the number of protons in its nucleus. Most elements have differing numbers of neutrons among different atoms these are referred to as isotopes.

There are 18 groups that make up The Periodic Table of Elements.

The beta decay of uranium-237 can be represented by the equation: (^{237}{92}U \to ^{237}{93}Np + e^- + \bar{\nu_e}) where (^{237}{92}U) decays into (^{237}{93}Np), an electron (e^-), and an electron antineutrino (\bar{\nu_e}).

The element Francium (Fr) could be considered the "rude one" on the periodic table due to its highly unstable and reactive nature. Francium is very rare and has no practical uses due to its extreme radioactivity and quick decay.

Without the periodic table, scientists would have a harder time organizing and understanding the properties of elements. It would be challenging to predict how elements would react with each other and to develop new materials. Progress in chemistry and other fields reliant on the periodic table would be hampered.

All group 14 elements share a valence electron configuration of ns2np2, where n is the principal quantum number of the valence shell. They can form covalent compounds, tend to have multiple oxidation states, and can act as both metals and nonmetals.

The groupings in the periodic table have some simalarities with the card game solitare. All the elements with similar properties are grouped in a vertical group, just as in solitare all cards of the same suit are arranged in a vertical group.

The most reactive metals in a group are typically found at the bottom left of the periodic table, such as alkali metals like cesium and francium. These metals have a single electron in their outermost shell, making them highly reactive and likely to form compounds with other elements.

No, francium is not the most explosive element in the periodic table. It is the most unstable and rarest naturally occurring element, but other elements, such as the alkali metals cesium and rubidium, are more reactive and can be more explosive under certain conditions.

Mn is the chemical symbol for the element Manganese. It is a transition metal with atomic number 25. Manganese is commonly used in steel production and is essential for many biological processes in plants and animals.

Element number 35 on the periodic table is bromine (Br). It is a halogen, typically found as a diatomic molecule in its elemental form. Bromine is a reddish-brown liquid at room temperature with a strong, unpleasant odor.

The charge for bismuth (Bi) is typically +3.

That is not a very precise question. I will assume first, that you mean metallic elements, since 'metals' would include brass, bronze, pewter, and steel! The other thing that would be needed are sharp dividing lines between "very reactive" and "fairly reactive", and between metallic and semi-metallic elements. And finally, does the question mean [b]always[/b] found as ores? Copper [b]can[/b] be found as the metal in nature, but it is now very rare, and copper ores are the usual source of copper metal. Gold is nearly always found as the metal, but there is a rare gold telluride ore.

Have a modern (IUPAC) periodic table in front of you for the rest of this answer.

Group 1 contains only very reactive metals. Be from group 2 is arguably only fairly reactive; the other elements in this group are very reactive. Group 3, including all of the lanthanide and actinide elements, would count as very reactive, as would Ti from group 4. Zr and Hf are borderline between fairly and very reactive. Groups 5 to 12 would all count as fairly reactive metals, but Os, Ir, Pt, Au are usually found as metals rather than ores, while Ru, Rh, Pd, Ag, Hg, and Cu are sometimes found as metals. From group 13 Al and Tl count as very reactive, Ga and In as very/fairly borderline, while B is not a metal. In groups 14, 15, and 16, only Sn, Pb, Bi, and Po could be counted as metals, and they would only be fairly reactive. There are no metals in groups 17 and 18.