Unit 1: fundamentals of science
The periodic table has seven periods with the metal elements to the left and the non-metals to the the right, the elements are arranged in order of their atomic number. In the periodic table the period is horizontal and the vertical columns are groups. The group 1 metals are the reactive elements and unreactive non-metals are in group 0.
The group 1 elements are alkali metals with 1 electron in the outer shell. The boiling and melting point decreases going down the group. Its elements have a low melting and boiling points, as the large atomic size results in weaker forces between the atoms next to it. The group 7 elements are halogens with 7 electrons in the outer shell. The halogens are non-metals therefore it has a low melting and boiling points. The boiling and melting point increases going down the group. For example, fluorine has the lowest boiling and melting points. Group 0 are noble gases which are unreactive because of the arrangements of the electrons and has low boiling points.
Relative atomic mass tells you how many protons there are in an atom whereas the mass number tells you the total number of proton and neutrons in an atom.
Atomic and electronic structures:
Atomic structure is 3
Electronic structure is 2s1
Atomic structure is 11
Electronic structure is 3s1
Atomic structure is 18
Electronic structure is 3s2 3p6
Atomic structure 20
Electronic structure is 4s2
Atomic structure is 48
Electronic structure is 4d10 5s2
Atomic structure is 30
Electronic structure is 3d10 4s
Bohrs model of the atom is explained as an atom that has a positively charged nucleus with the electrons that have a negative charge orbiting the nucleus.
Ionic bonding is when a non- metal and a metal react together, the metal atom loses electrons to form a positively charged ion and a non-metal gains these electrons to form a negatively charged ion. However, a covalent bond is when non- metal atoms bond together to share their electrons.
Tetrahedral in the basis of organic chemistry is defined, as a carbon that has a valence shell of 4 electrons this means that it can form 4 covalent bonds. This causes the covalent bonds, 4 electrons to repel and to move further away which causes the electrons to form an arrangement of tetrahedral with a central carbon.
The periodic table was used before preparing the standard solution, as it was used to find the relative molecular mass of an atom. After you find the relative molecular mass of the atom you use the equation mass=number of moles x molecular mass, but the equation had to be rearranged to find number of moles which is mass /molecular mass. Once you found what the number of moles are, you use the equation concentration x volume.
Potassium carbonate is an ionic bond. The bond is formed with the atoms potassium that has 1 electron in its outer shell and oxygen that has 6 electrons in its outer shell. Therefore, the potassium transfers its electron to oxygen so it can have a full outer shell.
Sodium hydroxide is formed with an ionic bond, however hydroxide is a covalent bond as hydrogen and oxygen share electrons by bonding.
A standard solution has a defined concentration.http://passmyexams.co.uk/GCSE/chemistry/covalent-bond.html https://www.bbc.com/bitesize/guides/z84wjxs/revision/1https://en.wikipedia.org/wiki/Periodic_table