Yr 10 Chem Flashcards
Subshell Filling Order
Remember the triangle and the octet rule!
1s 2s 2p 3s 3p 4s 3d 4p 5s etc.
Periodic Table
Why does ionisation energy increase when moving left to right across a period?
More protons being added equals more attraction within the nucleus, pulling the shells and therefore the electrons closer to the nucleus. This creates the effect of requiring more energy from other atoms in order to ‘steal’ one of the atom’s electrons.
Periodic Table
Why does atom size decrease as you move left to right across a period?
There are more protons in the nucleus as you move left to right across the period, and this creates more attraction, bringing the electrons and their shells closer towards the nucleus. Thanks to this effect, atom size decreases.
Periodic Table
Why should atom size increase as you move down a group?
The increase of shells means that the radius of the atom grows each time.
What is Ionisation? What is ionisation energy?
Ionisation is the act of stripping an atom of its valence electron, or the act of an atom gaining an electron due to stripping an electron off another atom, giving that atom an ion.
Ionisation energy is the amount of energy required to strip an atom of its valence electrons.
What are the types of chemical bonds?
Covalent bonding = sharing (non-metal with non-metal; non polar and polar) Ionic bonding = transfer before becoming ions (non-metal with metal) Metallic bonding (metal with metal)
What is a catalyst? What is the difference between a catalyst and an accelerant?
A catalyst is a substance that accelerates a chemical reaction by creating an alternate pathway for the reaction, allowing it to proceed at a lower activation energy.
A catalyst is not consumed in the reaction, while an accelerant is.
What are the three things needed for a successful reaction?
Correct orientation
Successful collisions
Enough energy for activation
What are the types of reactions?
Synthesis: A + B = AB (eg. H2 + Cl2 = 2HCl)
Combustion: Oxygen + A = AOxygen
Decomposition: AB = A + B
Precipitation: AB(Liquid) + CD(Liquid) = CB(Liquid) + AD(solid), eg. AgNO3 + NaCl = NaNO3 + AgCl(s)
Single Displacement: AC + B = AB + C
Double Displacement: AB + CD = AD + CB
How does temperature affect the rate of reaction?
Changes in temperature affect correct orientation, successful collisions and enough energy for activation. Temperature directly gives/takes away energy, speeding up or slowing down atoms. Together, this allows more/less chance for correct orientation and successful collisions (as they are moving faster/slower).
How does a catalyst affect rate of reaction?
A catalyst affects the activation energy required, as a catalyst creates an alternate pathway for the chemical reaction that has a lower amount of energy required to activate the reaction.
How does surface area, pressure and concentration affect the rate of reaction?
All three of these variables affects successful collisions and, in turn, correct orientation. Increasing the surface area allows more atoms to interact with each other, creating more successful collisions. Pressure speeds up particles, creating more successful collisions, while concentration increases the amount of atoms available in the same volume.
What is a polyatomic ion?
A polyatomic ion is a group of atoms that has an overall charge, such as Ca(NO3)2 - otherwise known as Calcium Nitrate, where (NO3)2 is the polyatomic ion. A valency table is given on the test with the polyatomic ions and their names as we need.
Note: all polyatomic ions are covalently bonded!
What is the first step to balancing a worded chemical equation?
Eg. Lithium oxide
Check the periodic table for their ionic charge when having a full valence shell. Group 1 has a charge of +1, group 2 +2, group 3 +3. Most transition metals can have multiple charges and will often be written as Copper II for a +2 charge etc., but some have only one specific ion. Remember to check your valency table to make sure! Group 8 (aka the last group) will never be included as they always have a full valence shell! Group 7 has a charge of -1, group 6 -2, group 5 -3. With group 4 you need to check the valency table, as they do not usually form ions. Remember the subshell stuff and you should be fine!
What is the second step to balancing a worded chemical equation? Eg. Lithium oxide
Lithium has an ionic charge of +1 as it is in Group 1, and oxygen has a charge of -2. The next step is to make sure the equation equals zero. You can add more atoms - eg. Two lithium atoms have a charge of +2 - but you cannot halve charges - eg. If you wanted a charge of -3 in oxygen to balance out with Copper III - which has a charge of +3 - you can’t have half an oxygen molecule so that cannot be done. In cases such as this, finding the lowest common multiple between the two is the way to solve this problem (yes… MATHS!)
