History of Atom
How did Indians and Greek philosophers discovered that atoms exist?
Through philosophical reasoning and experiment.
Be
Beryllium
Hydrogen
Group 1
Carbon
6
What bonding shares electrons?
Happens with two non metal
Covalent bonding
When did Thompson suggest a new atomic model?
1904!
C
carbon
Calcium
Group 2
Fluorine
9
When a metal and a non metal gains or looses their electron.
Ionic Bonding
Who devised the periodic table?
Dmitri Mendeleev
Si
Silicon
Helium
Group 18
Scandium
21
Why does covalent bonding have a weaker bonding than ionic?
Covalent bonds are weaker than ionic bonds because they involve sharing electrons without full charge attraction, while ionic bonds have strong electrostatic forces between oppositely charged ions.
What was Rutherford's experiment and what did he find out?
The gold foil experiment where he shot alpha-particles at the this sheet of gold. His prediction was that all the alpha-particles would go through but surprisingly, some of the particles bounced back. This suggest that atoms are mostly empty, but has tiny positively charged particles in the nucleus which is the center.
Fe
Iron
Tungsten
Group 6
zinc
30
Why do ionic compounds have higher melting points than covalent compounds?
Ionic bonds are stronger than covalent bonds, so they need more heat to break.
Who discovered rhenium?
Ida Tacke and Walter Noddack
Rf
Rutherfordium
Darmstadtium
Group 10
Molybdenum
42
Why do covalent compounds often not conduct electricity?
Because covalent compounds have no free ions or electrons to carry electric current.