Curly arrows - Study guides, Revision notes & Summaries

Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates participate in and is the scheme which was used by them in this examination. The standardisation process ensures that the mark scheme covers the students’ responses to questions and that every associate understands and applies it in the same correct way. As ...

When is the Assume Referential Integrity option available, and what does it accomplish? 1) Available in the Edit Relationships menu when connected to data source(s) using DirectQuery 2) Enables queries on the data source(s) to use INNER JOIN statements rather than OUTER JOIN, which improves query efficiency What are the requirements for using the Assume Referential Integrity option when connecting to data? 1) Data in the 'Many' side of the table relationship (foreign key) is never ...

MARK SCHEME – A-LEVEL CHEMISTRY – 7405/1 – JUNE 2021 9 3 3.14 Organic reaction mechanisms Curly arrows should originate either from a lone pair of electrons or from a bond. The following representations should not gain credit and will be penalised each time within a clip. H3C Br _ : H C . Br H3C . .Br .. _ OH OH For example, the following would score zero marks H H3C C Br HO H When the curly arrow is showing the formation of a bond to an atom, the arrow can go directly to...

AQA A-LEVEL CHEMISTRY PAPER 2MARKING SCHEME JUNE 2022 AQA A-LEVEL CHEMISTRY PAPER 2MARKING SCHEME JUNE 2022 A-level CHEMISTRY 7405/2 Paper 2 Organic and Physical Chemistry Mark scheme June 2019 Version: 1.0 Final *196A74052/MS* Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme in...

3.1 Introduction (No Questions) 3.2 Algorithms 3.1 Specifying the order in which statements are to be executed in a computer program is called (a) an algorithm (b) transfer of control (c) program control (d) pseudocode ANS: (c) 3.2. The two key attributes of an algorithm are: a) actions and start activity b) flow and order of flow c) actions and order of actions d) flow and start activity ANS: (c) 3.3 Pseudocode 3.3 Which of the following is true of pseudocode programs? ...

A-level CHEMISTRY 7405/1 Paper 1 Inorganic and Physical Chemistry Mark scheme June 2021. 3.12 Organic structures Where students are asked to draw organic structures, unless a specific type is required in the question and stated in the mark scheme, these may be given as displayed, structural or skeletal formulas or a combination of all three as long as the result is unambiguous. In general • Displayed formulae must show all of the bonds and all of the atoms in the molecule, but need not s...

Which compound has the highest boiling point? A ethanol B heptane C sodium chloride D water Your answer [1] 2 Pauling electronegativity values for the halogens F to I and some elements in period 2 of the periodic table are shown below. B 2.04 C 2.55 N 3.04 O 3.44 F 3.98 Cl 3.16 Br 2.96 I 2.66 Which bond has the correct polarity? A B C D δ– N—I δ+ δ– C—F δ+ δ– B—Cl δ+ δ– Br—Cl δ+ Your answer [1] 3 © OCR 2021 Turn over 3 Which compound release...

AQA A-level CHEMISTRY 7405/1 Paper 1 Inorganic and Physical Chemistry Mark scheme June 2021 Version: 1.0 Final  the cyanide ion or CN– when the reagent should be potassium cyanide or KCN;  the hydroxide ion or OH– when the reagent should be sodium hydroxide or NaOH;  the Ag(NH ) + ion when the reagent should be Tollens’ reagent (or ammoniacal silver nitrate). In this example, no credit is given for the ion, but credit could be given for a correct observation following on f...

AQA A-Level CHEMISTRY 7405/2 Paper 2 Organic and Physical Chemistry Mark scheme June 2022. MARK SCHEME – A-LEVEL CHEMISTRY – 7405/2 – JUNE 2022. Organic reaction mechanisms Curly arrows should originate either from a lone pair of electrons or from a bond. The following representations should not gain credit and will be penalised each time within a clip. H3C Br H3C Br H3C Br . . . . OH OH .. _ _ : For example, the following would score zero marks H3C C H H Br HO When the ...

AQA A-LEVEL CHEMISTRY 7405/2 PAPER 2 MARK SCHEME A-level CHEMISTRY 7405/2 Paper 2 Organic and Physical Chemistry Mark scheme Version: 1.0 Final *206A7405/2/MS* Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates...