{"id":14197,"date":"2022-11-18T16:00:42","date_gmt":"2022-11-18T10:30:42","guid":{"rendered":"https:\/\/www.aplustopper.com\/?p=14197"},"modified":"2022-11-19T16:21:06","modified_gmt":"2022-11-19T10:51:06","slug":"physical-chemical-properties-group-18-elements","status":"publish","type":"post","link":"https:\/\/www.aplustopper.com\/physical-chemical-properties-group-18-elements\/","title":{"rendered":"Physical and Chemical Properties of Group 18 Elements"},"content":{"rendered":"
Physical and Chemical Properties of Group 18 Elements<\/strong><\/h2>\n
Elements in Group 18 of the Periodic Table are: \nHelium, Neon, Argon, Krypton, Xenon, Radon \nThese elements are known as noble gases.<\/strong><\/p>\n
Physical properties of noble gases<\/strong><\/h3>\n
1.<\/strong> Table shows some physical properties of Group 18 elements.<\/p>\n
\n\n
\n
Element<\/strong><\/td>\n
Helium<\/td>\n
Neon<\/td>\n
Argon<\/td>\n
Krypton<\/td>\n
Xenon<\/td>\n
Radon<\/td>\n<\/tr>\n
\n
Proton number<\/strong><\/td>\n
2<\/td>\n
10<\/td>\n
18<\/td>\n
36<\/td>\n
54<\/td>\n
86<\/td>\n<\/tr>\n
\n
Atomic radius (nm)<\/strong><\/td>\n
0.050<\/td>\n
0.070<\/td>\n
0.094<\/td>\n
0.109<\/td>\n
0.130<\/td>\n
–<\/td>\n<\/tr>\n
\n
Melting point (\u00b0C)<\/strong><\/td>\n
-272<\/td>\n
-249<\/td>\n
-189<\/td>\n
-157<\/td>\n
-112<\/td>\n
-71<\/td>\n<\/tr>\n
\n
Boiling point (\u00b0C)<\/strong><\/td>\n
-269<\/td>\n
-246<\/td>\n
-185<\/td>\n
-152<\/td>\n
-107<\/td>\n
-62<\/td>\n<\/tr>\n
\n
Physical state<\/strong><\/td>\n
Gas<\/td>\n
Gas<\/td>\n
Gas<\/td>\n
Gas<\/td>\n
Gas<\/td>\n
Gas<\/td>\n<\/tr>\n
\n
Density (g dm-3<\/sup>)<\/strong><\/td>\n
0,18<\/td>\n
0.84<\/td>\n
1.66<\/td>\n
3.73<\/td>\n
5.89<\/td>\n
9.73<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
2. Atomic radius (atomic size)<\/strong><\/p>\n
\n
The atomic radii (atomic sizes) of noble gases increase when going down Group 18 <\/strong>from helium to radon.<\/li>\n
This is because the number of shells<\/strong> occupied with electrons increases when going down the group.<\/li>\n<\/ul>\n
3. Melting and boiling points<\/strong><\/p>\n
\n
All noble gases have very<\/strong> low melting and boiling points. They exist as gases<\/strong> at room temperature and pressure.<\/li>\n
Explanation:<\/strong>\n
\n
This is because noble gases consist of single atoms<\/strong> (monoatomic molecules) held together by weak van der Waals forces of attraction.<\/strong><\/li>\n
Only a small amount of heat energy<\/strong> is required to overcome the weak interatomic forces of attraction during melting and boiling.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
Trend of change down the group<\/strong><\/p>\n
\n
The melting and boiling points of noble gases increase when going down Group 18.<\/strong><\/li>\n
Explanation:<\/strong>\n
\n
This is because the atomic sizes<\/strong> of the noble gases increase<\/strong> when going down the group from helium to radon, thus the van der Waals forces of attraction between the atoms become stronger.<\/strong><\/li>\n
Hence, more heat energy<\/strong> is required to overcome the stronger interatomic forces of attraction during melting and boiling.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
4. Density<\/strong><\/p>\n
\n
All noble gases have very low densities.<\/strong><\/li>\n
The densites of noble gases increase when going down Group 18.<\/li>\n<\/ul>\n
5. Solubility<\/strong><\/p>\n
All noble gases are colourless gases which are insoluble in water.<\/p>\n
6. Electrical and heat conductivity<\/strong><\/p>\n
\n
All noble gases cannot conduct electricity.<\/li>\n
All noble gases are poor conductors of heat.<\/li>\n<\/ul>\n