I have a few questions about the Periodic Table?

Question

Row 1 on the periodic table is most reactive and the last row which is row 18 is the least reactive.

Heres a periodic table if you want to see it.

http://en.wikipedia.org/wiki/Periodic_Table

1. I want to know, which row do the atoms stop being reactive or would consider the atoms not as active?

2. How do you find out how many electrons an atom has?

Answer 1

actually its the coulmns that are predictive of reactivity.  Colums 1 and 17 are most reactive, then 2 and 16, ect.

further down in your post is a table that shows what shell the electrons fill.  Once the other most shell is filled, the element is inert.  If the shell is 1 away from being full or has only 1 electron in the shell, that element is very reactive, then with 2 missing or only 2 in the shell a little less.

The atomic number is the number of electrons also, ie H is 1, He is 2...

Answer 2

If you are taking Chemistry, you MUST learn to be more precise with your terminology.  The "rows" you refer to are NOT rows.  They are GROUPS, and in math, would be referred to as columns.  

1.  There are a few factors at work in the periodic table.

The table reactivity is restricted to reactions with other elements.  

The most reactive elements are those which most readily ionize.   On this basis, reactivity tends to reduce from both ends towards the middle, and increases with increasing period levels.   The Group 18 elements, the "rare gases" were considered inert to compound formation until 50 years ago, at which point flouride and oxyfluoride compounds of radon and xenon were comfirmed.

  The periodic table includes two groups of elements which should be excluded from the analysis; the d-transition metals and the f-transition metals.  While these metals are listed within one period, their identity is based on the number of electrons in a sub-shell of a lower-numbered period.  For example, after Calcium, whose outer electrons are 4s2, the next element is Scandium, which also has a 4s2 configuration, but has a 3d1 electron, which calcium lacks.  The transition metals behave generally similiar to each other in a given group.  

  As for electrons, the atomic number indicates their total.  

Answer 3

1. All the atoms, except the Noble Gases (row 18) are at least somewhat reactive.  In fact, if you cover up the last row, they're most reactive at the edges and least reactive in the middle.  But there's not really a definitive limit to say where elements are 'reactive' or 'not reactive,' just some are more reactive than others.

2. If an atom is sitting alone, not bonded with any other atoms or ionized, the number of electrons is the same as its atomic number.  For example, oxygen has 8 electrons, it's #8 on the table.

Answer 4

You have muddled up rows (across the way) and columns (down the way).

The elements in column (usually called Group) 18 are the least reactive, and are known as the noble gases.

The total number of electrons in an atom is equal to its atomic number.  The number of **valence** electrons is usually equal to its atomic number, minus the atomic number of the preceding noble gas. But sometimes you don't include d-electrons or f-electrons (you will be learning about these later).