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Periodic Table
The Periodic Table is a tabular arrangement of the elements in increasing order oftheir atomic numbers, so that elements with similar properties are in the same column. There are 18 columns, called groups, and seven rows, which are called periods, in the modern periodic table. Questions about the Periodic Table: its history and creation, trends, groups/families, and periods are asked in our Periodic Table category.
11,356 Questions
Bonding between elements in middle of periodic table tend to bewhat kind of chemical bonding?
Bonding between elements in the middle of the periodic table tend to be metallic bonding. In metallic bonding, outer electrons are delocalized and free to move, creating a "sea of electrons" that holds the metal ions together. This leads to properties such as high electrical and thermal conductivity in metals.
Gold is considered valuable for several reasons: it is rare, does not corrode, and has unique physical properties like being easily shaped and a good conductor of electricity. Additionally, gold has been culturally and historically prized for its beauty and symbolism, further increasing its value.
When did Moseley discovered Atomic Number?
1914
Using x-ray tubes, determined the charges on the nuclei of most atoms. He wrote"The atomic number of an element is equal to the number of protons in the nucleus". This work was used to reorganize the periodic table based upon atomic number instead of atomic mass.
How do sodium silicon and sulfur differ from another?
Sodium is an alkali metal with 1 very reactive electron in its outer shell, it tends to form ionic bonds.
Silicon is a semiconductor/pseudo-organic with 4 electrons in its outer shell, it tends to form covalent bonds.
Sulfur is a non-metal with 6 electrons in its outer shell, it tends to like to borrow other atoms electrons but also forms covalent bonds.
What is the smallest atom in the second row of periodic table?
The smallest element known to man is Hydrogen (H).
The mistake in this electron configuration is in the 5p subshell, where it shows 5p5 instead of 5p6. The correct element for this configuration is Xenon (Xe). The correct electron configuration for Xenon is [Kr] 5s2 4d10 5p6.
What are the elements in group two of the periodic table?
Group 2: alkaline earth metals 4
Be 12
Mg 20
Ca 38
Sr 56
Ba 88
Ra * Atomic radius increases as you go down the Group. Notice that beryllium has a particularly small atom compared with the rest of the Group. * Are very chemically reactive (give up 2 electrons during reactions) and are never found free in nature (same as alkali metals) * These metals form many compounds. They have ions with a +2 charge. Their atoms are smaller than those of the alkali metals. * found in the Earth's crust * they are so reactive * though radium is not always considered an alkaline on earth due to its radioactivity * The alkaline earth metals are silvery colored, soft, low-density metals, though are a bit harder than the alkali metals * two valence electrons and tend to lose both to form ions with a two plus charge * Berylium is the least metallic element in the group and tends form covalent bonds in its compounds. * These metals are less active than the alkali metals, but are still fairly active * react readily with halogens to form ionic salts * can react slowly with water. Magnesium reacts only with steam and calcium with hot water * Beryllium is an exception: It does not react with water or steam, and its halides are covalent The alkaline earth metals are named after their oxides, the alkaline earths, whose old-fashioned names were beryllia, magnesia, lime, strontia and baryta. These were named alkaline earthsbecause of their intermediate nature between the alkalis (oxides of the alkali metals) and the rare earths (oxides of rare earth metals). The classification of some apparently inert substances as 'earths' is millennia old
How many elements are there in the actinoid series?
There are 15 elements in the actinoid series, also known as the actinides. These elements follow actinium in the periodic table and include elements such as thorium, uranium, and plutonium.
How many molecules is in 291.25g of Pb's?
291.25 grams of lead (1 mole Pb/207.2 grams)(6.022 X 10^23/1 mole Pb)
= 8.4648 X 10^23 atoms of lead
I think you meant to say atoms, not molecules, as that is not a molecular formula and looks a lot like the symbol for lead with a possessive mark and s.
How can you tell what type of ion an atom will form by looking at the periodic table?
elements which have 1 to 3 valence electrons will generally lose electrons and form cations.
elements which need 1 to 3 electrons to attain the nearest noble gas configuration will generally gain electrons and form anions
HSeO3 is the chemical formula for selenous acid, a weak acid containing selenium in the +4 oxidation state. It is used in chemical synthesis and as a reagent in analytical chemistry.
What element has an atomic number of 74?
The atomic number is the same as the number of protons. So, from an atomic number of 74, we can conclude that there are 74 protons. One proton cancels out the charge of one electron, therefore, equal numbers of protons and electrons results in a neutral particle. For an atom with 74 protons to be neutral, 74 electrons are needed to balance.
How many elements in the first period?
Period 1: 2 elements
Period 2: 8 elements
Period 3: 8 elements
Period 4: 18 elements
Period 5: 18 elements
Period 6: 32 elements
Period 7: 25 elements
What atomic property affects periodic periodic trends down a group in the periodic table?
The phenomenon that comes into play as we go down toward the bottom of the periodic table through a group is electron screening. As we descend through a group, the atomic number of an atom increases, and so does the number of electrons shells. That means more electrons are between the nucleus (the positive charge) and the valence shell. You'll recall that the valence shell is the outer electron shell, and it is this shell and its population that largely determine the chemistry of an element. When atoms are larger with more electrons shells, the positive charge on the nucleus is "shielded" from the valence shell to a degree by the inner electron shells. That nucleus isn't "holding onto" the valence electrons as tightly. And in atoms that are electron "loaners" like those on the left side of the periodic table, the elements further down a group are "more willing" to loan out valence electrons. This means that they are more reactive. Electron screening serves to "interfere" with the grip the nucleus holds on the valence electrons for atoms farther down a group. On the right side of the periodic table, elements tend to be "borrowers" of electrons, and the translation of the effect of screening on the right is that the elements toward the bottom of a group are going to be less inclined to want to borrow an electron that elements higher up. Again, this is due to electron screening. If all of this is true, then the element of the bottom of Group 1, which is on the left of the table, will be the most reactive electron-loaning element. That's francium, and it is, indeed, the most reactive of the Group 1 elements. Conversely, on the right in the Group 17 elements (the halogens or halides), we'd expect the elements at the bottom to be less reactive than those at the top. And they are. The most reactive halogen is fluorine (at the top of the group), and it is the hungry wolf of the periodic table. Links are provided below.
What are the different sections of the periodic table called?
The sections that go up an down are called columns, groups, or families. The ones that go left to right are rows or periods.
1st column: (except for Hydrogen, it's a nonmetal) Alkali Metals
2nd column: Alkali Earth Metals
3rd column through 12th column: Transition Metals
Then nonmetals start at column 13 from Boron to Oxygen and follow down "steps" that outline these nonmetals. B, Si, As, and Te are the outlined "steps" of the nonmetals, and they are nonmetals.
Then Al down to Tl then to the right to Po outline other metals, and also follow the nonmetal "steps."
17th column: Halogens
18th column: Noble Gases
On the bottom of the table, there are two separated rows. The top row is known as the Lanthanide Series, and the bottom row is known as the Actinide Series.
How did mendeleev explain blank spaces left in his periodic table?
Mendeleev explained the blank spaces in his periodic table by predicting the existence and properties of elements that had not yet been discovered. He organized the known elements based on their atomic weight and properties, which allowed him to accurately predict the properties of missing elements. These predictions helped guide the discovery of new elements that filled in the empty spaces in the table.
What is chemical formula for copper 1 bromide?
The chemical formula for copper(I) bromide is CuBr. It is a compound that contains one copper ion with a +1 charge and one bromide ion with a -1 charge.
What is Group A called in periodic table?
In the older periodic table, each group was divided into A & B sub-groups. The only problem with that was that there were two different conventions about which elements were labelled "A" and which were labelled "B". Groups 1 & 2 were clearly 'A' (elements like sodium and calcium) and 11 & 12 were clearly 'B' (elements like copper and zinc). But groups 3 through 10 were labelled 'A' in one convention and 'B' in another, and the opposite labels were used for groups 13 through 18.
With the second labelling convention, groups labelled 'A' were known as 'main group elements', and groups labelled 'B' were 'transition metals', and that is still the case.
Thus in the newer IUPAC scheme, groups 1, 2, and 13 through 18 are called 'main group elements'.
Why atomic radii decrease as you move left to right?
The farther right you go along a periodic table, the more protons and elctectrons the atoms have. As the number of protons and electrons increases, the attraction between them increases, which draws the electrons closer to the nucleus (protons and neutrons), thus decreasing the atomic radii.
What Element in group 1 on the periodic table is not a metal?
Hydrogen is the only element in Group 1 that is not a metal. The other heavier metals in group one, Lithium, Sodium, Potassium, Rubidium, Cesium, and Francium are all called alkali metals, which are highly reactive since they do not have a full valence shell.
What metal is not malleable at room temperature?
All metals melt at high temperature... the metal that doesn't melt is mercury as it is already liquid at room temperature..... There is no metal that undergoes sublimation unlike non-metals.
What is a list of known elements arranged by atomic number and chemical properties?
The periodic table is a list of known elements arranged by atomic number and chemical properties. Each element is represented by its chemical symbol and organized into rows and columns based on similar properties. The arrangement helps scientists predict the behavior and characteristics of each element.
