Chemistry

Conversion form

SF₄ has sp³d hybridization and one type is axial while other type is equatorial

SiF₄ has sp³ (all bonds are equal)

$B{F}_4^{-}$ has sp³ (all bonds are equal)

XeF₄ has sp³d² and shape is sq. planar (All bonds are equal)

Viscosity of the hydrophilic sol is always higher than H₂O, because dispersed phase particle attracted by dispersion medium.

$R_{f}value=\frac{Distancemovedbysubstancefrombaseline}{Distancemovedbythesolventfrombaseline}=\frac{2}{5}=0.4=4.0*10^{-1}$

$\Delta H_{sub}ofNametal=496kJ/mole$

Bond dissociation energy of Br₂ = 228 kJ/mole

$\Delta H_f=495.8+-325-728.4=-557.6kJ/mole=-5576*10^{-1}kJ/mole$       

Note : In question is neglect ${\Delta }_a{H}^{0}ofNa,{\Delta }_{vap}{H}^{O}ofB{r}_2\left(l\right)and{\Delta }_{bond}{H}^{0}ofB{r}_2\left(g\right)$

$?H_{sub}of\text{?}\text{?}Na\text{?}\text{?}metal=496kJ/mole$

Bond dissociation energy of Br₂ = 228 kJ/mole

$?H_f=495.8+?325?728.4=?557.6kJ/mole=?5576*10^{?1}kJ/mole$           

Note :  ${?}_a{H}^0\text{?}\text{?}of\text{?}\text{?}Na,{?}_{vap}{H}^{O}of\text{?}\text{?}B{r}_2\left(l\right)and\text{?}\text{?}{?}_{bond}{H}^0\text{?}\text{?}of\text{?}\text{?}B{r}_2\left(g\right)$ In question is neglected

The early 20th century experiments on electrical discharge through gases eventually led to the discovery of cathode rays (electrons). The major finding was that the characteristics of these cathode rays (electrons) were independent of the material used for the electrodes and the nature of the gas present in the cathode ray tube. This consistent behaviour across different substances led to the conclusion that electrons are a basic constituent of all atoms.

Before 20th century, atoms were widely considered the indivisible building blocks of matter. This view goes back to Indian and Greek philosophies, as old as 400 B.C. It also became one established thought on a scientific basis by John Dalton in 1808. With his theory, several fundamental laws of chemistry were established. But those laws failed against observations like static electricity. The experimental observations made towards the end of the 19th and beginning of the 20th century definitively proved that atoms are made of subatomic particles.