Fundamental Chemistry Flashcards
Define compound
Two or more elements chemically bonded
Define element
Substance made up of only one type of atom
Mass of a proton
1 AMU
Mass of a neutron
1 AMU
Mass of an electron
Almost 0, 1/2000 AMU
Define mass number
Number of protons + neutrons
Define atomic number
Number of protons (in the nucleus)
Explain how a chlorine atom becomes a chlorine ion
Gains one electron
Explain how a sodium atom becomes a sodium ion
Loses one electron
Explain how an oxygen atom becomes an oxide ion
Gains two electrons
Explain how a magnesium atom becomes a magnesium ion
Loses two electrons
Charge of a proton
+1
Charge of a neutron
0
Charge of an electron
-1
Define a molecule
Two or more atoms bonded together
Formula of sodium hydroxide
NaOH
Formula of magnesium chloride
MgCl2
John Newlands and Mendeleev arranged their periodic table in order of…
atomic mass
The modern periodic table is arranged in order of…
atomic number (proton number)
Explain why Mendeleev left gaps in his periodic table
to make the pattern fit for undiscovered elements
Explain why potassium and sodium are in the same group of the periodic table
They both have one electron in their outer shell They react similarly
Describe how alkali metals react with water
-Bubble/Fizz/Effervesce -Turn indicator purple -Move about on the surface of the water -Sodium melts in a ball -Potassium burns with a lilac flame
Write a symbol equation for the reaction of sodium with water
2Na + 2H2O –> 2NaOH + H2
Name the typical properties of transition metals
-Good conductors of heat and electricity -Hard and strong -High density -High melting point -Form coloured compounds -Form ions with different charges (i.e. Fe2+ and Fe3+
Name one similarity and difference between the properties of copper and lithium
Similarities - conduct electricity Differences - lithium is more reactive, lithium is less dense, lithium is softer, lithium has a lower melting point
Describe the trend in reactivity of the group 1 metals as you go down the group
Reactivity increases
Describe the trend in melting point as you go down group 7
Melting point increases (fluorine is a gas, iodine is a solid)
Describe the trend in reactivity as you go down group 7
Reactivity decreases
Explain why chlorine and bromine are group 7 of the periodic table
Both have 7 electrons in their outer shell
Finish the following word equation Bromine + potassium iodide –>
Potassium bromide + iodine
Explain why chlorine can displace bromine from potassium bromide
chlorine is more reactive
Name the ion that turns universal indicator purple
OH-
Explain why potassium is more reactive than sodium
-Potassium has a greater atomic radius/more energy levels/more shells -there is less attraction between the outer electron and the nucleus/more shielding -Potassium loses an electron easier
Explain why fluorine is more reactive than chlorine
-Fluorine has a smaller atomic radius/less energy levels/less shells -there is greater attraction between the outer shell and the nucleus/less shielding -fluorine gains an electron easier
Name one use for the transition metals
Catalysts
Name pieces of apparatus A, B, C
What is the name of this separation process?
A = thermometer
B = condenser
C = (round bottomed) flask
Fractional Distillation
A student is given a mixture of salt and sand. Describe a method the student could do to separate the mixture naming the apparatus they should use.
- Pour the mixture into a beaker
- Add water to the beaker
- Stir until the salt dissolves
- Filter the mixture
- Remove the residue (sand)
- Dry the sand in an oven
- Place the filtrate (salt solution) in an evaporating basin
- Heat the solution with a Bunsen burner until the water evaporates
- Cool and dry the salt with an oven
Explain why chlorine’s relative atomic mass is 35.5
Relative atomic mass is an average mass
Chlorine exists as Cl- 35 and Cl-37
75% is Cl-35 and 25% is Cl-37
(35 x 75 ÷ 100) + (37 x 25 ÷ 100) = 35.5
Explain why Mendeleev swapped Tellurium and Iodine’s position in his periodic table.
- Iodine has similar properties to other group 7 elements
- Iodine had similar chemical reactions to other group 7 elements
- Iodine is also diatomic
What subatomic particle did James Chadwick discover?
Neutron
How did Mendeleev’s periodic table become accepted by scientists?
They discovered the elements he’d left gaps for
and they had similar properties to those he’d precited
