Chemistry Flashcards
Section 1 of Exam
What is the first group on the periodic table known as?
Alkali Metals
What is the second group on the periodic table known as?
Alkaline Earth Metals
What is group seven on the periodic table known as?
Halogens
What is group eight on the periodic table known as?
Noble gases
What is shell shielding?
The more shells in-between the electrons and the nucleus the weaker the bond and the more shell shielding.
What charge do neutrons have?
No charge (neutral)
What charge do electrons have?
Negative charge (-)
What charge do protons have?
Positive (+)
What is the atomic number?
The number of protons in an atom.
What is the atomic weight?
The number of protons + neutrons.
How do you find then number of electrons?
It is the same number as protons.
How do you find the number of neutrons?
Atomic weight - Atomic number.
How do you find the number of protons?
The atomic number.
How are elements arranged on the periodic table?
In atomic number order.
What is all matter made up of?
Atoms.
What subatomic particles are found in the nucleus?
Neutrons and protons.
What subatomic particle orbits the nucleus?
Electrons.
Who invented the Solid Ball model?
Democritus.
What model did Democritus invent?
The Solid Ball model.
Who invented the Plum Pudding Model?
JJ Thompson.
What model did JJ Thompson invent?
The Plum Pudding model.
Who invented the Nuclear model?
Ernst Rutherford.
What model did Ernst Rutherford invent?
The Nuclear model.
Who invented the Planetary model?
Neils Bohr.
What model did Neils Bohr invent?
The Planetary model.
Who discovered neutrons?
James Chadwick.
What subatomic particle did James Chadwick discover?
Neutrons. (Planetary model with neutrons)
True or False :The atom as the smallest unit of an element and that can be represented by a symbol
True ;)
Periods go: (across/down)
Groups go:
(across/down)
Periods go across.
Groups go down.
What is the period number also equal to?
The period number is equal to the number of shells on the atom.
What is the group number also equal to?
The group number is equal to the number of valence electrons.
What are valence electrons?
The electrons on the outermost shell.
What is an ion?
A charged particle that has lost or gained electrons.
Describe an electron configuration.
There can only ever be 2 electrons in the first shell and then 8 in each shell for the rest of them.
2, 8, 8, …. (Write like this)
What happens as you go down group one?
The elements become more reactive because there is more shell shielding, and they all only have to lose one electron to become stable.
Why is group 8 not reactive/stable? (Noble gases)
Elements in group 8 are stable/non reactive as they have full valence shells (all electron spots full).
What happens as you go down group 7? (Halogens pattern of reactivity)
The elements become more reactive because there is more shell shielding, and they all only have to gain one electron to become stable.
The periodic table is split into 2 sides, Metals and Non-metals, which side is which?
Metals are on the LEFT side and Non-metals are on the RIGHT.
True or False: Chemical reactions involve rearranging atoms to form new substances;
during a chemical reaction mass is not created or destroyed.
True ;)
When does a chemical change occur?
When old bonds between atoms are broken, the atoms are rearranged, and new bonds are formed.
True or False: Atoms can be destroyed and created.
False ;)
Ionic Bonding can only form between a _____ and a _____
Metal and a Non-Metal.
Covalent bonds can from between a _____ and a _____
2 Non-Metals.
Define an acid.
- Have a ph of less than 7
- (Strongest acids have a ph of 0)
- Acids contain H+ ions (Hydrogen)
Define an alkali/base.
- Have a ph of more than 7
- (Strongest bases have a ph of 14)
- Bases that are soluble (dissolve in water) are called (an) alkali’s
- Bases contain OH- ions (hydroxide)
Define a salt.
- A Neutral substance
-Substance produced by the reaction of an acid and a base.
What’s the difference between an alkali and a base?
Alkalis are bases that are soluble. (Can be dissolved in water)
What is the ph Scale?
A measure of how acidic or alkaline a solution is.
- Scale ranges from 0-14.
List 3 common acids. Include their chemical formula names.
- Hydrochloric Acid
HCl
-Nitric Acid
HNO3
-Sulphuric Acid
H2SO4
List 3 common bases/alkali’s.
Include their chemical formula names.
- Calcium hydroxide
Ca(OH)2 - Sodium Hydroxide
NaOH - Magnesium Hydroxide
Mg(OH)2
Acid + Alkali ➔ _____ + _____
Salt + Water
_____ + _____ ➔ Salt + Water
Acid + Alkali
Acid + Metal ➔ ______ + ______
Salt + Hydrogen
_____ + _____ ➔ Salt + Hydrogen
Acid + Metal
Acid + Metal Oxide ➔ _____ + ______
Salt + Water
_____ + ______ ➔ Salt + Water
Acid + Metal Oxide
Acid + Metal Hydroxide ➔ ______ + _______
Salt + Water
____ + ____ ➔ Salt + Water
Acid + Metal Hydroxide
Acid + Carbonate ➔ _____ + _____ + _____
Carbon Dioxide + Water + Salt
_____ + _______ ➔ Carbon Dioxide + Water + Salt
Acid + Carbonate
Balance this Equation:
Zn + O2 → ZnO
2Zn + O2 → 2ZnO
Balance this Equation:
NaOH + H3PO4 → Na3PO4 + H2O
3NaOH + H3PO4 → Na3PO4 + 3H2O
Balance this Equation:
H2SO4 + KOH → K2SO4 + H2O
H2SO4 + 2KOH→ K2SO4 + 2H2O
Name a very common antacid used to neutralize stomach acids.
Eno.
What is an antacid?
A type of medication that neutralizes stomach acid to relieve discomfort caused by acid-related conditions.
How do Antacids work?
Antacids work by raising the pH level in the stomach, making it less acidic.
What is the test for Carbon Dioxide? Outline.
The Limewater test:
-To test gases for CO2 you pass it through Limewater.
Limewater = calcium hydroxide, Ca(OH)₂)
-The presence of CO2 is confirmed if the limewater turns milky or cloudy
-This is due to presence of calcium carbonate. (CaCO₃), which is insoluble in water and precipitates out, causing the cloudy appearance.
What is the test for Hydrogen?
The Pop test:
- Hydrogen exposed to a flame makes a distinct popping sound.
-This occurs because hydrogen gas reacts explosively with oxygen in the air, forming water.
Explain an Endothermic Reaction:
- Heat transfers onto the object.
- The object is cooler than its surroundings.
- The object is left with more energy than when it started.
- Taking in heat = Taking in energy.
Explain an Exothermic Reaction:
- Heat transfers out from the object.
- The object is hotter than its surroundings.
- The object has less energy than when it started.
- Radiating heat = Losing energy.
Name 2 examples of an endothermic reaction:
- Ice Cube Melting
- Evaporation of Water
Name 2 examples of an exothermic reaction:
- Combustion of fuels
- Mixing Calcium Chloride with water.
Explain how cold packs work:
When ammonium nitrate (NH4NO3) is dissolved in water, it absorbs heat from the surroundings, causing the solution to feel cold. This reaction is commonly used in instant cold packs.
Explain how hot packs work:
Iron powder and water. Iron powder reacts with oxygen in the air, producing iron oxide (rust) and releasing heat in the process.
What are the 4 state symbols?
(l) Liquids
(g) Gases
(s) Solids
(aq) Aqueous
