How can the periodic table help you predict how atoms of different elements might combine?

Answer 1

This is taken from the wikipedia article on the Periodic Table located here : http://en.wikipedia.org/wiki/Periodic_table The main value of the periodic table is the ability to predict the chemical properties of an element based on its location on the table. It should be noted that the properties vary differently when moving vertically along the columns of the table, than when moving horizontally along the rows. * A group is a vertical column in the periodic table of the elements. Groups are considered the most important method of classifying the elements. In some groups, the elements have very similar properties and exhibit a clear trend in properties down the group - these groups tend to be given trivial (unsystematic) names, e.g. the alkali metals, alkaline earth metals, halogens and noble gases. Some other groups in the periodic table display fewer similarities and/or vertical trends (for example Groups 14 and 15), and these have no trivial names and are referred to simply by their group numbers. * A period is a horizontal row in the periodic table of the elements. Although groups are the most common way of classifying elements, there are some regions of the periodic table where the horizontal trends and similarities in properties are more significant than vertical group trends. This can be true in the d-block (or "transition metals"), and especially for the f-block, where the lanthanides and actinides form two substantial horizontal series of elements. == Modern quantum mechanical theories of atomic structure explain group trends by proposing that elements within the same group have the same electron configurations in their valence shell, which is the most important factor in accounting for their similar properties. Elements in the same group also show patterns in their atomic radius, ionization energy, and electronegativity. From top to bottom in a group, the atomic radii of the elements increase. Since there are more filled energy levels, electrons are found farther from the nucleus. From the top, each successive element has a lower ionization energy because it is easier to remove an electron since the atoms are less tightly bound. Similarly, a group will also see a top to bottom decrease in electronegativity due to an increasing distance between valence electrons and the nucleus. == Elements in the same period show trends in atomic radius, ionization energy, electron affinity, and electronegativity. Moving left to right across a period, atomic radius usually decreases. This occurs because each successive element has an added proton and electron which causes the electron to be drawn closer to the nucleus. This decrease in atomic radius also causes the ionization energy to increase when moving from left to right across a period. The more tightly bound an element is, the more energy is required to remove an electron. Similarly, electronegativity will increase in the same manner as ionization energy because of the amount of pull that is exerted on the electrons by the nucleus. Electron affinity also shows a slight trend across a period. Metals (left side of a period) generally have a lower electron affinity than nonmetals (right side of a period) with the exception of the noble gases. == All the elements of Group 18, the noble gases, have full valence shells. This means they do not need to react with other elements to attain a full shell, and are therefore much less reactive than other groups. Helium and neon are the most inert elements among noble gases, since reactivity, in this group, increases with the periods: it is possible to make heavy noble gases react since they have much larger electron shells. However, their reactivity remains very low in absolute terms. == In Group 17, known as the halogens, elements are missing just one electron each to fill their shells. Therefore, in chemical reactions they tend to acquire electrons (the tendency to acquire electrons is called electronegativity). This property is most evident for fluorine (the most electronegative element of the whole table), and it diminishes with increasing period. As a result, all halogens form acids with hydrogen, such as hydrofluoric acid, hydrochloric acid, hydrobromic acid and hydroiodic acid, all in the form HX. Their acidity increases with higher period, for example, with regard to iodine and fluorine, since a large I− ion is more stable in solution than a small F−, there is less volume in which to disperse the charge. == For the transition metals (Groups 3 to 12), horizontal trends across periods are often important as well as vertical trends down groups; the differences between groups adjacent are usually not dramatic. Transition metal reactions often involve coordinated species. == The chemical properties of the lanthanides (elements 57-71) and the actinides (elements 89-103) are even more similar to each other than the transition metals, and separating a mixture of these can be very difficult. This is important in the chemical purification of uranium concerning nuclear power.

Answer 2

Metals Period - reactivity decreases as you go from left to right across a period.

Group - reactivity increases as you go down a group Why? The farther to the left and down the periodic chart you go, the easier it is for electrons to be given or taken away, resulting in higher reactivity.

Non-metals Period - reactivity increases as you go from the left to the right across a period.

Group - reactivity decreases as you go down the group. Why? The farther right and up you go on the periodic table, the higher the electronegativity, resulting in a more vigorous exchange of electron.

Answer 3

the elements on the left hand and in the center of the periodic table are metals,on the right hand side are non metals and the elements separating the metals and non metals are metalloids. hence the arrangement of elements in the periodic table be used to predict how they react with the other elements to form compound.

Answer 4

The periodic table is organised based on the electron shell arrangement of each element's electrons. In column 1 (Group 1) all elements have 1 electron in it's outermost shell, all Group 2 elements have 2 in it's outer shell, etc. As you go down a group, the number of e- in the outer shell remains the same, but that outer shell is one shell further away i.e. there is another full shell in-between the e- and the nucleus. What this means, is that as you go further down the group, the electronegativity (or attracting power of the nucleus) to act upon the e- is very low, so it's tendency to 'get rid of' the electron is very high. Thus, Francium is the least electronegative.

Going across a period (or row), the outermost electron is in the same shell, but the number of electrons in that shell increases by 1 with each element (Li has 1, Be has 2 etc). The effect of having more p+ and more e-, is it brings the electron shells closer to the nucleus. This increases the electronegativity as you go left to right across a period.

So what does this mean? A highly electronegative atom will have a high tendency to 'steal' an e- from an element with less electronegativity. This is how elements react to form an ionic substance.

BOTTOM LEFT REACTS WITH TOP RIGHT. Bottom left is least electronegative, top right is most electronegative. Top right steals bottom left's electrons. Easy. :)

Answer 5

If an element has valence electrons, it is likely to react. The presence of valence electrons can be found by the electron configuration. Noble gasses does not react because the doesn't have valence electrons.

Answer 6

If an element is not stable, it can react. Elements react in order to achieve stability.

Answer 7

some are heavy and some are not

Answer 8

ask a gay person