Chapter 1 - Key Concepts In Chemistry Flashcards
What are the chemical formulas for: Water, Carbon Dioxide, Chlorine, Ammonia, Hydrogen and Oxygen?
H2O, CO2, Cl2, NH3, H2, O2
What. Are the ionic formulas for: Ammonium, Nitrate, Sulfate, Hydroxide, Carbonate
NH4(+), NO3(-), SO4(2-), OH(-), CO3(2-)
Note: the positives and negative as in the brackets are the charges and would normally be written like you would write ‘squared’ in maths
Name the four models of the atoms in order and there inventor
Atoms as solid spheres - John Dalton
The Plum Pudding Model - J J Thompson
The Nuclear Atom theory - Ernest Rutherford
The Bohr Model - Niels Bohr
Describe John Dalton’s atom model
Atoms were solid spheres and different spheres make up different elements
Describe J J Thompson’s Plum Pudding Model
There was a positively charged mass (the ‘pudding’) with negatively charged electrons scattered through it
Describe Rutherford’s atom model
A tiny positively charged nucleus at the centre surrounded by a ‘cloud’ of negative electrons -most of the atom is empty space
Describe Niels Bohr’s atom model
The electrons can only exist in fixed orbits (shells) and not anywhere in between them. Each shell has fixed energy. It is pretty close to the current model of the atom.
What are the three subatomic particles? What are their charges? What are their relative masses?
Protons, Neutrons and Electrons
P=+1, N=0, E=-1
P=1, N=1, E=negligible
What does the atomic number describe about an element? Does it have another name?
The number of protons in the atom (and electrons)
Th proton number
What are isotopes?
Different forms of the same element - they have the same number of protons but a different number of neutrons.
What makes isotopes the same element?
The atomic number (protons) is the same but its only the atomic mass number (neutrons) which changes
What is Ar? How can it be calculated?
Relative atomic mass. It is the average mass number from the isotopes.
(Isotopic mass X isotopic abundance) + (Isotopic mass X abundance)
/
100
Who arranged the First version of the Periodic Table and when?
Dimitri Mendeleev, 1869
What do the groups on the periodic table show?
How many electrons an element has on its outer shell
The elements with similar properties
What do the periods show in the periodic table?
How many electron shells/orbits/energy levels the element has
What does the atomic number represent? Does it have another name?
The number of protons (and also electrons)
The proton number
What does the relative atomic mass number represent? Does it have another name?
The number of protons and neutrons
The mass number, the atomic mass number
What are ions?
Charged particles. They can be single atoms or groups of atoms.
Which elements are most likely to form ions?
1,2,6,7
What happens to the electrons in ionic bonding?
They are transferred from a metal to a non-metal. The oppositely charged ions are strongly attracted to each other by electrostatic forces of attraction. This attraction is called an ionic bond.