Topics 1,2 And 3 Flashcards
(46 cards)
What are the electrons in an atom?
- move around the nucleus
- negative charge
- tiny
- no mass
- occupy shells
What is the charge on electrons?
The same as proton charge but opposite (negative)!
How many protons and electrons in an atom?
Equal amount
What are the characteristics of protons?
Heavy
Positively charged
What are the characteristics of neutrons?
Heavy
Neutral
What are the characteristics of electrons?
Tiny
Negatively charged
What is covalent bonding?
Sharing electrons - forming a molecule
Give two elements that were discovered by spectroscopy
Rubidium
Caesium
What test could you use to distinguish between a solution of sodium chloride and magnesium sulfate
Chloride - add dilute nitric acid and silver nitrate - will give a white precipitate of silver chloride
Sulfate - add dilute HCL and barium chloride solution - gives a white precipitate of barium sulfate
What colour would a flame be if A) sodium B) potassium C) calcium were out into it?
A) yellow orange
B) lilac
C) brick red
Explain why barium sulfate can be drunk even though it’s toxic
It’s insoluble
Opaque to X-rays
When drunk it shows up the gut so that any problems e.g blockages can be seen
A forensic scientist carries out a flame test to identify a metal. The metal burns with a blue - green flame. Which metal does this indicate?
Copper
Name two insoluble metal chlorides
Barium sulfate
Calcium carbonate
Describe how you would prepare a pure, dry sample of the insoluble salt barium sulfate
Mix solutions of barium nitrate and potassium sulfate
Filter out the precipitate of barium sulfate
Wash it with distilled water
Dry on filter paper
What is the chemical formula for A) potassium fluoride B) aluminium chloride C) sodium hydroxide
A) k+F-
B) Al+ Cl-
C) Na+ OH-
Explain the difference between a compound whose name ends in ‘-ate’ and who’s name ends in ‘-ide’
When two different elements combine the components name is something ‘-ide’
When three or more different elements combine and one is oxygen it’s often something ‘-ate’
List the main properties of ionic compounds
Regular lattice structure
High melting and boiling point
They conduct electricity when aqueous or molten
Are cations positive or negative ions
Positive
Describe the process of ionic bonding
- The Transfer of electrons. Atoms lose or gain electrons to form positively or negatively charged atoms called ions
- Shell with one electron will want to get rid of it to have a full outer shell
- A nearly full she wants the extra electron to have a full outer shell
- Groups 1/2 and 6/7 are likely to form ions
What are the groups in the periodic table? Explain the significance in terms of electrons
- Alkali metals, transition metals, halogens, noble gasses.
- elements in the same group have similar number of electrons in their outer shell
- group number equal to the amount of electrons in the outer shell
Explain how Mendeleev arranged known elements in a table. How did he predict new elements?
- 50 know elements according to their properties
- similar chemicals in the Same vertical groups - left gaps to make this work
- the gaps predicted the properties of undiscovered elements
What feature of atoms determines the order of the modern periodic table?
- metals and non metals opposite sides
- order of increasing atomic number of electron shells
- the properties of the elements change as you go along the period
The element boron has 5 protons how many electrons does it have in its outer shell?
5
Name the 3 types of particle in an oxygen atom
Proton
Neutron
Electron
