Periodic Table

Now (January 2012) the periodic table of Mendeleev contain 118 chemical elements.

I assume you're talking about the periodic table. Group 18 are the noble gases, they have a full outer shell of 8 valence electrons, thus they are alreadystable. Every other element tries to have a full outer shell like the noble gases.

there are five element in group 16 of the periodic table

The water table is present below the Earth's surface within the zone of saturation, where surface water infiltrates and fills the spaces between rocks and soil. Its depth can vary depending on factors such as geology, climate, and human activity.

The alkali metals family correctly labels the elements in group 1 on the periodic table. This group includes elements such as lithium, sodium, and potassium.

yes, it is in there to give you energy! :)

The periodic table organizes all of the elements by their physical and chemical properties, so elements with similar properties go in the same vertical column, or group or family, i.e. the Alkali earth metals are the first column of the periodic table, all of the elements in that group are highly reactive with water, and will either fizzle or explode when dropped in water. Therefore, scientists can use the other elements in a group to predict the properties of another element in the group that they do not know about.

Also, there are periodic trends in the horizontal rows of the table, called periods. For instance, the atomic radius of the elements is the biggest on the left, and gradually gets smaller as you move to the right.

Hope this helps! :)

Dimitri Mendeleev arranged the known chemical elements into a systematic chart known as the Periodic Table. By organizing the elements by atomic number and properties, this table allows for predictions of the behavior and characteristics of elements within each group.

The symbol on the periodic table means the abrevitation of the chemical element. For example, the chemical element symbol Pm stands for Promethium.

Element names come from a variety of sources. * Some of them are traditional names (silver, gold, sulfur) predating the modern notion of elements. * Some of them are named after their properties (oxygen comes from a phrase meaning "acid former" since it is present in many mineral (and all organic) acids; caesium comes from a word meaning "sky blue" for the color of a line in its emission spectrum). * Some of them are named after the material or location where they were first discovered (helium comes from a word meaning "sun" since it was first discovered by its emission lines in the solar spectrum; samarium comes from the mineral samarskite, from which it was first isolated. * The most recent trend is to name them after scientists (einsteinium, curium, seaborgium). Element symbols are usually abbreviations of the name in some sense. The basic rules are "no repeats, no more than two letters, first letter capitalized, second letter (if there is one) lower case" and beyond that it's pretty much anything goes. The abbreviation may not be related to the name of the element in English; for several elements it comes from the Latin name and in at least one case (tungsten) the abbreviation comes from the German form of the name: W, for wolfram. For elements that have not yet been discovered and/or given official names, there are placeholder names and symbols based on the digits in the atomic number. The digits zero through nine are represented by nil, un, bi, tri, quad, pent, hex, sept, oct, en and the (three-letter) abbreviation is the first letter of each digit. In this scheme, element 118 is ununoctium with symbol Uuo.

The chemical equation representing the reaction of magnesium (Mg) with oxygen (O2) to form magnesium oxide is: 2Mg + O2 → 2MgO The "c" in your equation does not have a clear designation in this context.

The group number tells you the number of valence electrons in the outer shell. This is important because it is the valence electrons that participate in bonding, and thus in determining the properties of the element.

Bromine (Br2) is the third most reactive halogen.

Let us do this in two parts for clarity. Find atoms in tin first.

10 grams tin (1 mole Sn/118.7 grams)(6.022 X 1023/1 mole Sn)

= 5.07 X 1022 atoms of tin

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5.07 X 1022 atoms (1 mole Pb/6.022 X 1023)(207.2 grams/1 mole Pb)

= 17 grams of lead

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I can see two other ways to do the conversion string, one longer and one much shorter. See if you can find them.

hydrogen has the least mass of all the elements, so yes in a way, it is.

Yes, hydrogen is on its own in the periodic table as the first element. It is the lightest and simplest element, with atomic number 1 and symbol H.

Thulium is an lanthanide element with atomic number 69.

This song, originally sung by Tom Lehrer, mentions 102 elements. The lyrics can be found online.

While theoretical approaches like computational chemistry can provide insights into reaction mechanisms, experimental validation is necessary to confirm the proposed mechanism. Experimentation allows for the observation of intermediates, rate laws, and other key details that are crucial for elucidating the complete reaction pathway. Theory and experiment are often combined to develop a comprehensive understanding of reaction mechanisms.

Copper is in the top-right of the transition metals section of the table, in between zinc and nickel.

The symbol is Cu and the atomic number is 29.

CH4 is not on the periodic table because the periodic table only lists individual elements, not compounds. CH4 is a chemical compound made up of one carbon atom and four hydrogen atoms, so it is not listed as a single element on the periodic table.

on moving down the group the atomic size as well as nuclear charge inreases.But the effect of increase in atomic size is much more pronounced than that of nuclear charge and thus the additional electrons feels less attraction consequently electron gain enthalpy becomes less negative on going down the group

The metals, except for mercury, which is liquid at room temperature.

Parentheses are used for the formula Al(OH)3 to indicate that the hydroxide group (OH) is grouped together and that there are three of them bonded to the aluminum atom. This notation helps to clarify the composition and structure of the compound.

The halogens are located in Group 17 of the periodic table. They include elements such as fluorine, chlorine, bromine, iodine, and astatine. Halogens are highly reactive nonmetals with seven valence electrons.