Integrated Science Periodic Table

Integrated Science & Periodic Table Atoms are the smallest particles used in order to identify an element. These elements are made up of only one specific kind of atom (Chang 2010). The difference between a mixture and a compound lies in the fundamentals of what makes up both substances. A compound is a substance that contains more than one element, but in fixed proportions, making it a molecule.

No matter how large or small the amount of compound, the proportions will always have to be the same in order for the substance to qualify as a specific compound made up of the molecules (Chang 2010). For example, water is a molecule containing, one oxygen atom and two hydrogen atoms. The combination of these specific atoms in specific proportions is what makes it a compound. If the elements forming this compound were to be broken up, the compound itself would change therefore we would no longer have water.

A mixture on the other hand is not dependent on proportions or compositions. It is the mixing of various elements or molecules, but changing the proportion of each will not change the overall mixture (Chang 2010). For example, milk is a mixture of fat, protein, and sugar. Adding water to this will not change the fact that it is milk -- it'll just be less pure.

If a pure substance were to be had, one can tell if it is indeed a compound or element by attempting to break it down even further. As previously stated, a compound is the combination of elements or molecules in specific proportions. If a pure substance is not able to be broken down anymore, then it only contains one element. However, if the substance is able to be separated into more than one element, then it is considered to be a compound (Chang 2010).

There are two commonly known types of bonds: ionic and covalent. An ionic bond forms when ions come together to form a compound. Every atom contains a nucleus of neutrons (neutrally-charged particles) and protons (positively charged particles). Even though these particles are able to be separated, it takes an immense amount of energy to remove a proton or a neutron (Chang 2010). However, an atom also contains electrons, which are negatively charged particles.

Because these particles are not directly part of the nucleus, but are instead orbiting the outside of the nucleus, they are able to be removed more swiftly. An ionic bond is the removal or addition of electrons when combing with other elements (Chang 2010). Removing a proton would change the element altogether, but adding an electron would make it more negatively charged (anion) or removing an electron would make it more positively charged (cation) (Chang 2010). An ionic bond is held together by the attractive forces that exist between the elements.

While ionic bonds gain or lose electrons, a covalent bonds share them. The valence electrons that surround each element are shared among two or more elements (Chang 2010). Ionic compounds are formed when a metal from the left side of the periodic table reacts with a nonmetal from the right side. Metals from the left side of the periodic table have the tendency of losing electrons in order to stabilize itself.

Because the ionization energy from left to right increases, the lower the ionization energy, the easier it will be for these metals to lose their valance electrons, making it favorable for them to combine and react with elements from the right side of the periodic table (Chang 2010). These elements are the opposite of the left side elements.

These ionization energies are much higher, therefore it is easier for them to gain an electron from another element to form a compound, than it is for these elements to give a valance electron up. These right-sided elements are called non-metals. However, these non-metals are further broken up into categories. Elements in group VII are called halides or salts because of their tendency to react with the elements from group I in order to form salt ionic compounds (Chang 2010).

Examples of this include sodium fluoride (Na+ and F-) and sodium chloride (Na+ and Cl-) which is table salt. Noble gases, which are the elements in the final group, have complete valence shells, so they do not pair well with the left-sided elements, although they do belong to the non-metals group (Chang 2010). This is also due to their high ionization energies which make it impossible to break these elements apart or to give or take an electron. Octets are formed when an atom has a full valence shell.

That is, an element is more stable if the number of electrons surrounding the nucleus has a sum of eight (Chang 2010). This is what covalent bonds are all about. Nonmetals from.