Transition metals
Because they will lose electrons and hence have positive oxidation numbers.
No, this is not the case. Firstly, a simple substance (pure element) always has oxidation number 0. Then there is the fact that when combining with an element more electronegative than the element in question it will tend to have a positive oxidation number while if the element is more electropositive it will tend to have a negative oxidation number.Nitrogen is a good example:-3 in NH3-2 in N2H4-1 in NH2OH0 in N2+1 in N2O+2 in NO+3 in NaNO2+4 in NO2+5 in HNO3Other elements are not as versatile as nitrogen, but a typical non-metal will show all odd or even oxidation numbers over a range of 8 units, as well as zero, while a typical metal will show all odd or even oxidation numbers between 0 and its valence.The elements that do show only one common oxidation number (other than zero) are all of the s-block elements and fluorine and oxygen.
Group 17 elements are also known as halogens. Atomic halogens have 0 as their oxidation number. They tend to accept an electron from another element to become stable: the new oxidation state would be -1.
Why does group 4A elements tend to form covalent bonds rather than ionic bonds? 
metals
Because they will lose electrons and hence have positive oxidation numbers.
No, this is not the case. Firstly, a simple substance (pure element) always has oxidation number 0. Then there is the fact that when combining with an element more electronegative than the element in question it will tend to have a positive oxidation number while if the element is more electropositive it will tend to have a negative oxidation number.Nitrogen is a good example:-3 in NH3-2 in N2H4-1 in NH2OH0 in N2+1 in N2O+2 in NO+3 in NaNO2+4 in NO2+5 in HNO3Other elements are not as versatile as nitrogen, but a typical non-metal will show all odd or even oxidation numbers over a range of 8 units, as well as zero, while a typical metal will show all odd or even oxidation numbers between 0 and its valence.The elements that do show only one common oxidation number (other than zero) are all of the s-block elements and fluorine and oxygen.
They all tend to form multiple covalent bonds.
they all tend to form multiple covalent bonds
they all tend to form multiple covalent bonds
All tend to form multiple covalent bonds. A+
they all tend to form multiple covalent bonds
they all tend to form multiple covalent bonds
they all tend to form multiple covalent bonds
Outer electrons are the electrons that are borrowed or stolen in a reaction. Because a non-metal has a negative oxidation number, it will borrow electrons from a metal to complete its outer shell. Metals have positive oxidation numbers and tend to lose electrons in reactions.
Group 17 elements are also known as halogens. Atomic halogens have 0 as their oxidation number. They tend to accept an electron from another element to become stable: the new oxidation state would be -1.
yes, this is called oxidation