Chapter 1.1 Chemistry For Life Flashcards
Define anion
Negative ion formed when an atom gains electrons
Define cation
Positive ion, formed when an atom loses electrons
What is ionic bonds ?
Attractive forces between oppositely charged ions
How is a covalent bond formed ?
When atoms share electrons to have full outer shell
What is a dipole ?
Separation of charge in a molecule when the electrons in covalent bonds are not evenly shared
What is a polar molecule ?
A molecule containing a dipole
What is a hydrogen bond?
Weak electrostatic intermolecular bonds formed between polar molecules that contains at least 1 hydrogen atom
What is atom made up of?
Nucleus which contains protons and neutrons as well as electrons
Why does an atom with full outer shell not take part in chemical reactions?
Because it is stable so there’s no need to get electrons or to give electrons
What happens in order for atoms to have ionic bonding?
Atoms must gain or lose electrons
Is ionic bonds easy to break?
No. Ionic bonding has a strong intermolecular forces between the atoms
What happens in covalent bonding ?
Atoms share electrons to have a full outer shell
True or false. Covalent bond is weak
False. Covalent bonds are very strong.
What does it mean when molecules in covalent bonds are polarised?
The electrons in the covalent bonds are not evenly shared so the molecule has a part that is slightly negative and slightly positive part.
In order for molecules to have polarity what atom is needed?
Hydrogen atoms
What happens when ionic substances dissolve in water ?
The ions separate
Does most ionic substances exist as a positive or negative ions in the cell?
Yes. This is because cells are 60-70% water. So ionic substances can dissolve
Give formula for nitrate ions
-
NO3
Give formulae for phosphate ions
-3
PO4
Give formula for chloride ions
-
Cl
Give formula for hydrogen carbonate
-
HCO3
What is nitrate ions needed for?
Needed for plants for the formation of amino acids