Periodic Table

Nominally atomic mass, but in practice he knew this wasn't strictly correct and "cheated" a little based on chemical properties in a couple of cases (he thought the measured masses were wrong).

Mendeleev predicted that there would be three additional elements to be discovered based on the gaps in his periodic table at the time. These elements turned out to be later discovered and were named gallium, scandium, and germanium.

There are either 118 or 117 elements in the peiodic table. it depends on the one that you are looking at.

In each element's box on the periodic table, you can typically find its atomic number, chemical symbol, atomic mass, and perhaps its name. It may also include the element's electron configuration and the period and group number to which it belongs.

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Moving down a group, the elements will have the same number if valence electrons. Tis will give them similar properties, such as the Noble Gases, or the extreme reactivity of Group I metals. Moving across a period, elements will begin to resemble each other less and share fewer properties the further apart they are in the row.

The symbol "24mg2" likely refers to the magnesium ion with a +2 charge. Magnesium has 12 electrons in a neutral atom, but since it has a +2 charge, it has lost 2 electrons, giving it 10 electrons in total when it becomes a Mg2+ ion.

Atomic symbols are used to represent elements, a negative (-) and a psoitive (+) represent electrons and protons, respectively. Chemicals or other compounds are often written as a combination of atomic symbols with subscripts to indicate the presence of multiple atoms.

the smallest atom is hydrogen, the smallest molecule would be the naturally occurring diatomic hydrogen.

Hydrogen is an element that is located in the p-block on the periodic table, but based on its properties, it should be with the s-block elements. This is due to hydrogen's ability to lose an electron to form a positive ion, similar to alkali metals found in the s-block.

Bismuth is sometimes referred to as a "cruel joke" because of its name, which sounds like "bis + myth" and could be interpreted as meaning "not a myth" when it actually is a real element.

Plutonium is dangerous because it is a radioactive element that emits high-energy alpha radiation which can damage cells in the body if ingested, inhaled, or absorbed. It is also toxic, with chemical properties that make it harmful to living organisms even in small amounts. Additionally, plutonium has a long half-life, which means it remains radioactive for a very long time, posing a threat to the environment and human health.

No. The position of an element in the periodic table cannot predict the number of isotopes it has. However, the position of an element in the periodic table can predict other properties like the charge of its ion, the formula of its oxide, the acidic or basic nature of its oxide, etc.

When alkali metals react with water they produce an alkali (basic) solution.

No because they form basic oxides and they neutralise acids

One of the main defects of Rutherford's experiment was that the atomic model he proposed (with a dense, positively charged nucleus at the center orbited by electrons) could not explain the stability of atoms and the continuous emission of electromagnetic radiation. Additionally, his model did not account for the distribution of electrons in the atom and the specific energy levels they occupy. Finally, Rutherford's experiment did not incorporate quantum mechanics, which is essential for describing the behavior of particles at the atomic level.

On planet earth, silicon is the second most abundant element. It comprised 28 percent of the earth's crust. The most abundant is oxygen, which makes up about 47 percent of the earth's crust. The second most abundant element in the universe is helium.

Group 1 elements, also known as alkali metals, tend to form positive ions by losing one electron to achieve a stable electron configuration. Additionally, group 2 elements, or alkaline earth metals, also form positive ions by losing two electrons.

Gold was discovered a long time before Mendelejev submitted his ideas in the 'Periodic table of elements'. So this can't have been the earliest discovery.

Gold is already known from Egyptian hieroglyphs (2600 BC). In Egypt and especially Nubia were the earliest gold-producing areas. The earliest known map is known as the Turin Papyrus Map and shows the plan of a gold mine in Nubia together with indications of the local geology (cit. from wikipedia).

In 1869 Russian teacher and scientist Dmitri Mendeleev, presented a periodic table of the elements based on atomic weights. The current periodic table is arranged by the atomic numbers of the elements.

"In" in the periodic table stands for the element indium. It is a soft, malleable metal with a shiny silver luster. Indium is used in a variety of applications, such as in electronics and solar panels.

As you move across a period on the periodic table, the atomic number of the elements increases. This means that the number of protons in the nucleus increases, leading to a stronger positive charge in the nucleus. As a result, the attraction between the positively charged nucleus and the negatively charged electrons increases, which affects the size of the atom.

Lead's symbol Pb is an abbreviation of its Latin name plumbum for soft metals; originally it was plumbum nigrum, where plumbum candidum was tin. The English word "plumbing" also derives from this Latin root.

The list of all known elements is called the periodic table. It organizes elements based on their atomic number, electron configuration, and chemical properties.

Groups on the periodic table go horizontally from left to right. Each group represents elements with similar chemical properties due to the arrangement of their electrons in the outer energy level. These groups are also known as families.

Elements in the same group or column on the periodic table have similar properties. This is because they have the same number of valence electrons, which determines their chemical behavior. For example, all elements in Group 1 (such as lithium, sodium, potassium) share similar properties due to having one valence electron.