Answer:
Metallic bonds
Explanation:
Metallic bonds joins atoms of metals and atoms of alloys together. The copper used in making pennies is a metallic substance so it contains metallic bonds.
- The formation of this bond type is predicated on the large atomic radius, low ionization energy and large number of electrons in the valence shell.
- The bond is an attraction between the positive nuclei of all closely packed atoms in the lattice and the electron cloud.
- The electron cloud is jointly formed by all the atoms by losing their outermost shell electrons.
This way the bond in pennies are metallic in nature.
P: Good conductor of heat and electricity - R: the delocalized electrons are
free to move around the structure
P: High melting and boiling points - R: the bonds in metals are very strong
P: Ductile (can be stretched and squashed) - R: because the electrons are free to move, the atoms can slide over each other.
P: Malleable (can be hammered into shape) - R: the bonds in metal don't break easily
Answer:
CH4 < CH3CH3 < CH3CH2CH3
Explanation:
Alkanes are saturated aliphatic hydrocarbons that undergoes intermolecular Van der waals forces. Van der waals forces are the attractive forces which make it possible for non-polar molecules to form liquids and solids.
Van der waals force are described as intermolecular forces arising from induced fluctuating dipoles in atoms and molecules brought about by movement of electrons around the atomic nucleus.
An example of the Van der waals force is the london dispersion force that occurs in the alkane family. It is the weakest of all electrical forces that act between atoms and molecules, These forces are responsible for liquefaction or solidification of non-polar substances at low temperature.
The strength of the intermolecular forces is based on the number of electrons surrounding the molecule and the surface area of the molecule. SO, in alkanes, the longer the carbon chain, the more stronger the intermolecular forces.
<span>In the given chemical equation, 4 moles of nh3 gas react with 5 moles of oxygen to form 6moles of water vapours (h2o). Hence each mole of nh3 contributes to production of 1.5 moles of water vapours.
therefore, the rate of formation of h2o is 1.5*0.5 ms-1, i.e 0.75 moles/sec</span>
