We can prevent rust by electroplating, painting, greasing, etc
100
What are the basic properties of non-metals ?
Poor thermal conductors, Poor electrical conductors, Brittle solids, little or no metallic luster, Gain electrons easily
100
Tell some properties of metalloids which make them different from the rest ?
They have properties of metals and non metals both together they are good metals till a certain point and have good non metal properties till a certain point of time
100
Why do noble gases dont react
Because their outer most shell is filled to the maximum- they are stable
100
Why do we use atomic number than atomic mass ?
We use atomic number because, it is hard to remember the mass of each and every element because, it can get in decimals and 2 different elements can have the same mass.
200
Why does metals rust and not non-metals?
Metals come in contact with water and oxygen – give an electron – cause rust
Non metals dont as they dont have an extra electron to give to oxygen
200
Which are the two things that are conducted badly in non-metals ?
Heat and Electricity
200
Why are metalloid semiconductors of heat ?
Metalloid's form bond which are easily broken by heat only one or 2 max .this provides electrons for passage of current they arent as good as other conductors as they form a resistance after a certain point
200
Atomic mass boiling point increase as we go down the group why so ?
As we move further the structure is changing and more electrons are added
200
How was the law of octaves different from the way Mendeleev arranged the elements on the periodic table ?
Mendeleev arrange according to the atomic number where as in law of octaves it was arranged according to increasing atomic weight with similar physical and chemical properties occur after each interval of seven elements
300
Why in metals does the atomic radius increase from right to left and top to bottom ?
The atomic radius increases as there are additional layers of electron and 1 more electron is added.
300
Why is hydrogen considered a non-metal if it can form positive ions like metals ?
Because hydrogen is neutral and has one proton and one electron.
300
Which element is used in making computer chips and why only that element ?
because it has properties of metals and non-metals both- does not conduct heat very well is solid at room temperature and has a high melting point as when a electronic is heavily used they stay together
300
Will noble gas be able to create fire ?
They will not be able to create fire as they are non-flammable as they don’t react with oxygen.
300
Why are metals taking majority of the periodic table ?
Metals take the majority of the periodic table because, metals are high amounts and are used everyday.
400
Why are metals such as lithium and sodium so reactive with water ?
As it is more active with hydrogen and clue to formations of covalent bonds there is gain and lose of electron making it more violently.
400
Does non-metal reflect light ?
No because they have no metallic luster
400
What is something common between alkali metals and metalloids ?
As we go down the group the melting point decreases in both of them and the atomic radius increases
400
which noble gas is used for making lights ?
neon
400
How was the grouping of triads rejected ?
It did not support the finding of new elements.
500
Why do metals such as calcium react slowly with water ?
As the hydrogen and oxygen molecules are split resulting in some of the hydrogen atom to be released in some...
500
How many valence electrons does non-metals have ?
5-8
500
Can metalloids form alloys if yes why and if no why ?
They can form alloys because since metalloids acts like a metal it combines with other metals to form an alloy.
500
Why is noble gases appropriate to use in the lightings ?
Noble gases are commonly used in lighting because of their lack of chemical reactivity and will glow when electricity is passed through it.
500
How long after Dmitri Mendeleev made the periodic table was finally accepted ?