Booklet 1 - structure Flashcards
What is a atom?
Smallest part of an element that can exist. It cannot be divided
What is an element?
Substance that contains only one type of atom
What is a compound?
Substance that contains more than one type of atom, chemically bonded together
What are valencies?
Combining powers of atoms and can be used to work out the formula of compounds
What are radical groups?
Atoms that like to group together with other atoms and stay with each almost all the time including chemical reactions
What is a molecule?
Two or more atoms chemically bonded together
What is a mixture?
Two of more substances (elements or compounds) that are not chemically bonded together
What is the formula, valency and charge of Ammonium?
NH4 - 1 - postive 1
What is the formula, valency and charge of Sulfate?
SO4 - 2 = -2
What is the formula, valency and charge of Hydroxide?
OH - 1 = -1
What is the formula, valency and charge of Nitrate?
NO3 - 2 = -2
What is the formula, valency and charge of Carbonate?
CO3 - 2 =-2
What is the formula, valency and charge of Hydrogen Carbonate?
HCO3 - 1 = -1
How can mixtures be separated? (3 examples)
1) . Silicon dioxide from water by filtration
2) . Salt from water by evaporation or distillation
3) . Dyes in ink by chromotography
What’s the atomic number?
Number of protons
What can both protons and neutrons be called?
Nucleons as they both exist in the nucleus
What are the two most important thing about the atomic number?
1) . All elements of the same type have the same atomic number
2) . All atoms identity depends on the number of protons in its nucleus
What is an isotope?
Atoms of the same element, they have the same number of protons but different amount of neutrons so their mass number is different
What is the relative atomic mass?
An avergae value that takes account of the abundance of the isotopes of the isotopes if the element.
When is the arrangement of electrons most important?
When considering how an element reacts, or whether it will react at all
What are the physical properties of Group 8/0 noble gases?
- All unreactive, wont set on fire
- the boiling points of the gases increase as you move down the group along with increasing relative atomic mass
- they are colourless gases at room temperature
- have ions with different charges
- form coloured compounds
- useful at catslysts
Why don’t noble gases react?
Have full outer shells so do not need to move electrons between themselves and other atoms = already have stable electron configuration
What the physical properties of Group 1 elements alkali metals?
Metals with low density
Soft and can be cut with a knife
Show a shiny interior that becomse dull on reaction with oxygen
Why are Group 1 elements so reactive?
The outer electron is more easily lost as the attraction between the nucleus and the electron decreases, as the electron is futher away drom the nucleus the futher down you go
Whay are the word and symbol equations of Group 1 elements reacting with water? (Lithium, sodium, potassium)
1). Lithium + water -> lithium hydroxide + hydrogen
2 Li + 2 H2O -> 2 LiOH + H2
2). Sodium + water -> sodium hydroxide + hydrogen
2 Na + 2 H2O -> 2 NaOH + H2
3). Potassium + water -> potassium hydroxide + hydrogen
2 K + 2 H2O -> 2 KOH + H2
What is the pattern with group 1 element reactions?
All react to produce hydrogen gas and an alkali metal hydroxide
What are the word equations for Group 1 elements reacting with chlorine?
1). Lithium + chlorine -> lithium chloride
2 Li + Cl2 -> 2 LiCL
2). Sodium + chlorine -> sodium chlorine
2 Na + Cl2 -> 2 NaCl
3). Potassium + chlorine -> potassium chloride
2 K + Cl2 -> 2KCl
What are the word equations for Group 1 elements with oxygen?
1). Lithium + oxygen -> lithium oxide 4 Li + O2 -> 2 Li2O 2). Sodium + oxygen-> sodium oxide 4Na + O2 -> 2 Na2O 3). Potassium + oxygen -> potassium oxide 4 K + O2 -> 2K2O
What do all alkali metals that burn in oxygen form?
Metal oxides which are white solids
What are the physical properties of Group 7 the halogens?
They are non metals and consist of molecules that are diatomic
What happens to molecules futher down the group in Group 7?
The higher the mass of its molecules, its melting and boiling points also increase
What is the reactivity of group 7 elements like?
Its harder to gain an extra electron, and its futher from the nucleus so it becomes LESS reactive as you go down the group
What is a halogen that gains a electron called?
A halide ion
What are the trends of Group 1 elements and Group 7 elements?
The bigger and more energy levels the atoms have:-
- In Group 1 elements the more easily electrons are lost
- In group 7 the less easily electrons are gained
What happens to Group 1 elements the higher up the group an element is?
The lower its atomic number
How many electrons are in Group 1 outer shell?
1 electrons
How many electrons are in Group 8/0 outer shell?
Full 8 electrons
How many electrons are in Group 7 outer shell?
7 electrons
What are the two other trends for group 1 elements?
- lower melting and boiling points
- higher relative atomic mass
What is the trend for group one elements reacting with water?
The more reactive (lower down the group) an alkali metal is, rhe more violent the reaction
- the amount if energy given out by the reacrion increases down the group
What are the trends of group 1 elements with chlorine?
- when heated in chlorine gas they form white metal chloride salts
- as you go down the group the reactivity increases so the reaction gets more vigorous
Why do group 1 metals tarnish in air?
Upon reaction with oxygen, the metal reacts and forms a dull metal oxide layer
What are the differences between group 1 and transition elements?
- group 1 elements are much more reactive than transition metals, they react more vigorously with water, oxygen and group 7 elements
- they’re also less dense, strong and hard than transition metals and have lower melting points
What type of do halogens form when they react with metals?
Ionic bonds
Why do Group 0 elements boiling points increase as you go down the group?
Due to an increase in the number of electrons in each atom leading to greater intermolecular forces between them which need to be overcome
What can a more reactive halogen do?
Displace a less reactive halogen from an aqueous solution of its salt
what are the relative charges of particles in the atom?
- proton - +1
- neutron - 0
- electron - -1
what are the relative masses of particles in the atom?
- proton - 1
- neutron - 1
- electron - very small
how can halogens share electrons with other non-metals?
via covalent bonding and make simple molecular structures
