C1 Atomic structure Flashcards
What is the radius of an atom?
About 0.1 Nanometres
10^(-10) m
How do you calculate the number of protons from an atomic symbol?
You look at the Atomic number
What is an isotope?
Different forms of the same element, which have the same number of protons but a different number of neutrons
How do you calculate Relative atomic mass?
Isotope abundance times isotope mass number over the sum of abundances of all the isotopes
What is the difference between a mixture and compound?
Compound - Multiple elements chemically bonded
Mixture- multiple elements physically bonded
Why do we need to balance equations?
Through the law of conservation of mass, we know that all the mass in the reaction has to go somewhere, it cant just disappear
How to balance an equation?
The numbers in proportion for the amount of the elements/compounds must be the same, so make sure the reaction makes sense
What is the stationary and mobile phases for the chromatography required practical
Stationary: Chromatography paper
Mobile: Solvent
What is the process for a simple distillation?
1: The solution is heated. The part of the solution that has the lowest boiling point evaporates first
2: The vapour is the cooled, condenses in the condenser ( turns back into a liquid) and is collected
Who made the theory that atoms were solid spheres?
John Dalton at the start of the 19th century
Who concluded that atoms were based in the “plum pudding” model
JJ Thomson in 1897
Who used the famous alpha particle scattering experiment to conclude atoms were mostly empty space
Ernest Rutherford in 1909 alpha particle scattering experiment
In the Rutherford alpha particle scattering experiment, why did some of the particles seem to be changed in their trajectory?
The positive charge of the alpha particles and the positively charged nucleus both repelled each other so the alpha particles trajectory was altered.
Who discovered the neutron?
James Chadwick
Why are group 0 atoms inert?
They already have a full outer shell so they dont need to react to gain another one
Who first innovated on the periodic table to make it more modern
Dmitri mendeleev
Why did Mendeleev leave gaps in the periodic table?
Gaps were left in the table to ensure that elements with the same properties stayed in their appropriate group
What does the group number in the periodic table tell you?
How many electrons in the outer shell
What does the period number in the periodic table tell you?
How many shells is in the atom
what are some properties of transition metals?
- They form coloured compounds
- They form multiple charged ions
- They make good catalysts
What is the trend in reactivity going down the 1st group in the periodic table
-It gets higher
What is the scientific name for the 1st group of the periodic table
Alkaline metals
What are the trends of Group 7 of the Periodic table
- Lower reactivity as you go down the group
- Higher melting and boiling points
- Higher relative atomic mass
What were the conclusions/observations from the Rutherford alpha particle scattering experiment?
Observations:
- Most particles went straight through
- Some particles were deflected
Conclusions:
- Atoms mostly empty space
- Concentrated positively charged mass in centre
Why did the of Gallium support mendeleevs periodic table
- Proved his predictions of galliums properties to be correct
- Gallium fit in to the gap in the periodic table
