C4: Chemical Patterns Flashcards
What does the nucleus of an atom contain?
Protons and neutrons
What is the relatibe mass and charge of a neutron?
1 and has no charge
What are the state symbols for each state.
Liquid (l), Soild (s), Gas (g), Aqeuous (aq)
Describe how heating a metal can help to identify it
When heated some elements porduce flames with an distinctive colour. EG: LI - RED, NA - YELLOW/ORANGE, K - LILAC. Can be used to identify metal in a compound, if placed in blue bunsen flame.
What can line spectrums be used for?
It can be used to identify elements because each element has a unique spectra, also to discover new elements.
What size groups did Dobereiner organise the elements into?
Triads - groups of three
Give two reasons why Newlands’ octaves were criticised
Some groups didnt contain elements with similar properties and metals& non metals were mixed up. He also didnt leave any gaps
Why did Mendeleev leave gaps in the periodic table?
For undiscovered elements and used the gaps to predict the properties of these undiscovered elements.
What features of atoms determines the order?
Atomic Mass
What is significant about the properties of elements in the same group?
They had very similar properties in vertical groups.
What are the rows in the perodic table known as?
Periods
How many electrons can the first shell of electrons hold?
2
Explain why elements in group 1 form postive ions and those in Group 7 form negative ions.
In group 1 they have 1 electron on the outer shell, they want a full outer shell so they lose a electron, making them postively charged. Group 7 have 7 on the outer shell and want to gain a electron to achieve a full shell. This extra electron means it is negatively charged.
DEFINE: Ionic Bonding
Ionic bond is the chemical bond between two ions with opposite charges.
What kind of structures do ionic bonds from?
Ionic compounds from a regular lattice shape of ions
The formula of magnesium bromide is MgBr2. Bromide ions have a charge of 1-. What is the charge of Magnesium?
2+
What group are the alkali metals?
Group 1
As you go down the alkali metals, what happens to reactivity?
Reactivity increases as you go down
Give details of reactions between the alkali metals and water
When they are put in water, they react vigorously, they float and fizz. The reaction produces a alkaline solution and hydrogen gas.
Atoms in Group 7 go around in pairs what is this called?
Diatomic
Describe how reactivity changes as you go down group 7
Reactivity decreases, it is oppsite to group 1 They also have a higher melting and boiling point.
Describe the appearance of chlorine at room temperature
Dense green gas
Name a type of experiment that could be used to determine the relative reactivity of the halogens.
Displacement reaction
What precautions need to be taken when working with group 7 elements? Why?
They are harmful and toxic. Fluorine is too dangerous to use in a lab. Liquid bromine is corrosive. They all give off poisionous vapours taht irritate the respiratory system and the eyes. They must be used inside a fume cupboad so you dont breathe in the fumes.
