C4 Flashcards
What is an element?
Made up of only one kind of atom. All the atoms of an element have the same number of atoms.
How were the elements in the modern periodic table arranged?
In order of increasing proton number.
Different elements have different…
Proton numbers.
What can you see from looking at the periodic table?
- Relative atomic mass- total number of prtons and neutrons in an atom
- Symbol and name
- Atomic(proton) number)
What is an atomic proton number?
The number of protons (and number of electrons) in an atom.
How many electrons does Group 1 elements have in its outer shell?
1
3 examples of G1 elements?
Li, Na, K
How many electrons does Group 7 elements have in its outer shell?
7
Which group are diatomic molecules? What is the formula?
The halogens (Group 7)- F2, C2,B2 and I2
Halogens are toxic and ________
Poisonous
What increases as you go down group 7?
Melting and Boiling Points
What precautions should be taken when dealing with halogens?
Gloves and glasses and the room should be ventilated.
What is the formula for when halogens react with G1 to form salts?
2y + x^2 —–> 2yX X=G7 Y=G1
Do the reactions become more or less vigerous down group 7?Why is this?
Less because the outer electrons are further from the nucleus so less attracted so it is harder to gain an electron.
What did scientists identify elements as?
Chemicals that couldn’t be broken down.
What does every element in the periodic table have?
A set number of protons
Who has the periodic table in triads, where elements where in groups of 3 with similar properties?
Doberiener
Who had a periodic table in octets, where every 8th element had similar properties?
Newlands
What did Mendeleev realise when arranging the periodic table?
That some elements in groups with elements with very different properties.
What did Mendeleev do with elements what still had to be found in the periodic table?
Left gaps for them
What did Mendeleev predict about these undiscovered elements?
The properties
Was Mendeleev Correct?
Yes
What can data in the periodic table be used for?
To work out trends and to make predictions.
What do elements emit when they are heated?
Coloured flames
What colour does lithium emit?
Red
What developed discovery made scientists discover some elements, such as Helium?
Spectroscopy
What can the coloured light be split intro?
A line spectrum that is unique to each element.
How was Helium discovered?
When chemists looked at the line spectrum from the sun.
What charges do Protons, Neutrons and Electrons have?
Proton- 1 Neutron-0 Electron- -1
What masses do Protons, Neutrons and Electrons have?
Proton- +1 Neutron-+1 Electron- Almost 0
What number on the periodic table tells you the number of protons?
the atomic number
What number on the periodic table tells you the number of neutrons?
the relative formula mass- the atomic number
In an atom are the number of protons and electrons are different or the same?
the same
What do electrons in different shells have different?
Energy levels?
The closer the electron shell is to the nucleus the…
Lower the energy level
What happens to the number of electrons in the outer shell as you move across a period?
Increases
As you move from left to right along a period, elements have…
One more proton and one more electron.
What trends do you notice as you go across a period?
Properties, such as MP.
Wahat do group 0 elements have?
Full electron shells and are inert
What does inert mean?
Very reactive
Atom rules: The number of electrons in the outer shell of an atom is the…
Same as its group number on the PT.
Atom rules: Atoms of elements with up to 3 electrons in their outer shell…
are metals
Atom rules: Atoms of elements with 5 or more electrons in their outer shell are
non-metals
Atom rules: Elements with full outer shells are the…
Inert gases
What increases as you go down G1?
Reactivity
What is the re-activity of G1 elements linked to?
the single elctron in the outer shell. They all form ions with 1+ charge by losing an electron.
The outer shell is easiest to lose if…
The atom is bigger because the electron is further from the nucleus.
Do all group 1 elements react with water?
Yes
What is Lithium and Sodium’s reaction with water?
They fizz and move around on the surface.
What happens to the reaction with water as you go down Group 1?
It gets more violent.
What is formed when a G1 metal reacts with Water?
Hydrogen
What other compound (other than H) is made when a G1 metal reacts with water?
a metal hydroxide (OH), which is an alkali- it turns the indicator blue.
Group 1 metals are flammable and their hydroxides are…
Harmful and corrosive.
What is the equation for a G1 element reacting with water?
Metal + Water —-> Metal hydroxide + Hydrogen
How does Sodium react with Chlorine?
Vigorously- giving a yellow flame and makes a white solid (NaCl).
How do other G1 metals react with chlorine?
Vigorously- gets faster as you go down the group.
Sodium + Chlorine —>?
Sodium Chloride
What is the appearance of chlorine, bromine and iodine at room temp?
Chlorine- pale green gas Red- brown liquid Iodine-dark grey solid.
What does diatomic molecules mean?
That they have 2 atoms joined to each molecule.
What also increases as you go down Group 7?
BP and MP
When does a displacement reaction occur?
When a more reactive halogen takes the place of a less reactive halogen in a compound.
How many electrons do halogen atoms have in their outer shell?
7
What are ionic compounds? Give an example.
Compounds of a G1 element with a G7 element. (E.g. Sodium Chlroide)
ionic compounds are…
solids with high MP.
Why are these compounds called ionic compounds?
they contain charged particles.
How are charged particles in ionic compounds arranged?
In a crystal lattice.
Are ionic compounds soluble in water?
Yes
Do ionic compounds conduct electricity? Why?
Sometimes, but not when solid. This is because the ions must move to the electrodes to complete circuits.
What happens to the ions in an ionic crystal when they melt or dissolve?
The ions are free to move.
