Ions, Atoms and Isotopes ATOMS, BONDING AND MOLES Flashcards
What is an ion?
Usually, atoms neutral because they have the equal numbers of protons and electrons. However, sometimes atoms can lose or gain electrons, e.g. when metals react with non-metals. If an atom gains one or more electrons it gains an overall negative charge. If it loses one or more electrons you say that is has an overall positive charge because it has more protons that electrons.
What is an isotope?
Atoms of the same element with different numbers of neutrons are called isotopes. They will always have the same atomic number but different mass numbers.
Why might an isotope be radioactive?
The extra neutron makes it unstable.
What is different with isotopes properties?
They have different physical properties e.g. the density of the atoms.
They will always have the same chemical properties. This is because their reactions depend on their electronic structure. The electronic structure of isotopes remains the same.
What is the electronic structure of a stable ion?
2,8 or 2,8,8
Do non-metals or metals gain electrons?
Non-metal atoms gain electrons (Most commonly).
How can you show ionic bonding?
Dot and cross diagram
What is ionic bonding?
It is the transfer of electrons from a non-metal to a metal (or metal to non-metal) in order to get the stable electronic structure of a noble gas.
Why are the ions in giant ionic structure held together tightly?
Due to the strong attractive electrostatic forces between the oppositely charged ions that act in all directions.
Why do giant ionic structures have high melting and boiling points?
It takes a lot of energy to break up the strong bonds. There are lots of bonds to break. In order to separate this structure there are lots of electrostatic bonds to overcome.
Can a solid giant ionic structure conduct electricity?
No, because the ions are held in fixed positions in the lattice. They can only ‘vibrate’ on the spot.
Can giant ionic structures conduct electricity as a liquid?
Yes, they are are attracted to oppositely charged electrodes held in the molten compound.
When will ionic compounds conduct electricity?
When molten or dissolved in water. This is because the ions become mobile and can carry the charge through the liquid.
Give an example of a giant ionic structure?
Sodium chloride
