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66 Cards in this Set
- Front
- Back
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Where are the alkali metals? |
Group 1 |
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Why are they called alkali metals? (4 points) |
1. They are very reactive with oxygen, so they are stored in oil. 2. They are soft enough to be cut with a knife. 3. The most common ones (Lithium, Sodium, and Potassium) all float on water. 4. They react with water to form alkaline compounds. |
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What is the electron structure of alkali metals? |
They all have one electron in the valence (outer) shell. This means that they have very similar physical and chemical properties, and that they lose 1 electron to make an ion so they all have positive (+1) ions. |
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What are the properties of alkali metals? (5 points) |
1. Very soft and easy to cut with a knife. It gets softer down the group. 2. Low density. The density gets higher down the group. 3. Low melting and boiling points. 4. Conducts electricity 5. Is shiny when freshly cut |
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Trend in density? |
The density gets higher and higher down the group. It isn't perfect because Sodium is more dense than Potassium. |
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Trend in melting/boiling points? |
The melting/boiling points get higher, the farther down the group. This is because the atoms get larger, and the attraction between the electrons and the protons in the nucleus gets weaker. |
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How do they react with oxygen? |
Alkali metals react with oxygen in the air to form metal oxides. This produces a dull oxide layer on the outside of the metal known as tarnish. This is why they are stored in oil. The alkali metals tarnish faster, the lower down the group. |
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What does the reaction with water produce? (5 points) |
1. They react vigorously with water. 2. They react more and more the lower down the group. 3. It creates alkali metal hydroxide + hydrogen. 4. It is an exothermic reaction. 5. Universal indicator goes purple after reaction indicating a strong base. |
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How does lithium react with water? |
Lithium is the least reactive alkali metal. It fizzes and moves around on the surface of the water. |
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How does sodium react with water? |
The sodium melts as it reacts, and turns into a small sphere. The hydrogen sometimes catches fire, due to the high heat of the reaction. |
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How does potassium react with water? |
The reaction gives off so much heat that the hydrogen catches alight as a lilac flame. |
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How do alkali metals react with chlorine? |
They burst into flames when heated and added to chlorine. It forms an alkali metal chloride. |
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What are halogens? |
Elements in Group 7. |
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Why are they called halogens? (3 points) |
1. They are very reactive non-metals. 2. They are all toxic or harmful. 3. They are never found free in nature because of their reactivity-only as compounds with metals. |
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What is the electron structure of halogens? |
They have 7 electrons in their valence shell. This means that they form negative ions by gaining one more electron to have a full valence shell, and that they have similar chemical properties. |
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How do halogen molecules exist? |
Halogen molecules only exist as diatomic molecules. They form covalent bonds with another atom to form a diatomic molecule. |
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General Properties of halogens? |
1. Non-Metals 2. Brittle and crumble when solid 3. Poisonous and smelly 4. Become darker in colour down the group |
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Halogen Vapours? |
Bromine and iodine are not gasses, but have low boiling points. This means they make vapours at low temperatures. They are volatile. |
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How do halogens react with metals? |
The reactivity of halogens means that they readily react with most metals. Halogens and metals react to form an ionic compound. They are known as metal halides, which are a type of salt. |
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What are halides? |
When halogens react with another substance. their name changes slightly. The ending changes from "ine" to "ide". |
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What is the reactivity of halogens? |
The reactivity of halogens decreases as you go down the group. |
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How do halogens react with non-metals? |
Unlike their reaction with metals, halides form covalent bonds with non-metals, because they share electrons. |
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Displacement of Halogens |
If a halogen is added to a solution containing a less reactive halogen, it will react with the compound and form a new one. This is called displacement. A more reactive halogen always replaces a less reactive halide. eg fluorine + sodium chloride = sodium fluoride + chlorine |
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What are noble gasses? |
Group 0/18 in the periodic table. |
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Electron structure and reactivity of noble gasses |
All noble gasses have full valence shells. This means they are very stable and the most unreactive (or inert) of all the elements. They are monoatomic. |
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General Properties of Noble Gasses |
All of them are colourless, odourless and unreactive. This makes them difficult to isolate and identify |
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What are transition metals? |
They are the block of elements between groups 2 and 13. The word transition is used as in-between. |
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Why are they called typical metals? |
There are over 30 transition metals. They include familiar metals that we use every day like gold, copper, and iron. But there are also some that are not that well known because they are rare or have few uses. |
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What are physical properties of transition metals? (6 points) |
1. Lustrous (bright and shiny) 2. Hard and strong 3. High density 4. Malleable (can be bent and pressed into different shapes) and ductile (drawn into wires) 4. Good Conductors of heat and electricity 5. High melting/boiling points (except mercury) |
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How reactive are transition metals? |
They are much less reactive than alkali metals. They react very slowly. The general trend is for a decrease in reactivity from left to right across the periodic table. Exceptions are zinc and iron. |
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What happens to iron when it rusts? |
Rusting is an oxidation reaction between iron, water, and oxygen. It leads to the creation of hydrated iron (the chemical name for rust). Rusting is a type of corrosion. |
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Transition Metal Ions |
All transition metals form positive ions. |
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How are transition metal ions identified? |
The presence of transition metal ions in solution can be tested by adding sodium hydroxide solution. If transition metals are present it creates a metal hydroxide which is solid. This is known as a precipitate. |
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What is thermal decomposition? |
Compounds of transition metals can be broken down into simpler substances by heating them. This is called thermal decomposition. |
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Naming Simple Compounds (2 steps) |
For Compounds of metals and non-metals: 1. Write down the name of the metal 2. Write down the name of the non-metal but changing the ending of the word to -ide. eg Magnesium + Oxygen + Magnesium Oxide |
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Composition of Compounds |
A compound always contains a particular amount of each element. It has a fixed composition. The symbols of the elements in a compound are combined to give the formula of the compound. |
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What are bonds? |
Each element is made up of just one atom, joined to other atoms by bonds. |
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Why do atoms bonds? |
The atoms of noble gasses have completely full valence shell and so are stable. This means they don't make bonds usually. The atoms of other elements have incomplete valence shells, and so are unstable. By forming bonds, these elements are able to fill their valence shells and become stable. |
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What are the types of bonding? (3 points) |
1. Ionic Bonding: occurs between metals and non-metals. 2. Covalent Bonding: Occurs between non-metal atoms only. 3. Metallic Bonding: occurs between metals only |
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What is an ion? |
An atom or group of atoms that have electrical charge either positive or negative. |
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How do atoms become ions? |
Atoms have an equal number of protons and electrons, which gives it a neutral charge. Some atoms have incomplete valence shells, and gain or lose electrons to become stable. When this happens, they have unequal number of protons and electrons, this means they have a positive or negative charge. This is how atoms become ions. |
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Positive and negative ions? |
An atom that loses electrons has more protons than electrons and so is positive or a cation. An atom that gains electrons has more electrons than protons, and therefore is a negative or anion. |
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How do atoms form positive ions? |
Atoms with a nearly empty valence shell, lose electrons to become an ion, and are therefore positive. Positive ions have small '+' symbol and number indicating how many electrons have been lost. Metals form positive ions. |
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How do atoms form negative ions? |
Non-metals form negative ions. Negative ions have a small '-' symbol and a number by it to indicate how many electrons have been added. |
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What is a compound ion? |
Ions can be made up of single atoms or a group of atoms. An ion made up of a group of atoms is called a compound ion. |
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What is ionic bonding? |
This is usually between a metal and non-metal. Electrons are transferred from each metal to the non-metal to form complete valence shells. The positive and negative ions are strongly attracted to each other. This electrostatic attraction is called ionic bonding. |
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What is a force? |
A force is a push or pull. It cannot be seen. |
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Types of forces |
Gravity and magnetism are non-contact forces. Friction and upthrust are contact forces. |
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Measuring Forces |
Force is measured in Newtons (N). A forcemeter is an instrument that is used to measure forces. |
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What is friction? |
If you rub your hands together they get warm. It is because there is resistance to the rubbing motion. It is called friction. Friction tries to slow down moving objects. Friction is created whenever two touching objects move past each other. It also occurs in the air. It is called air resistance or drag. |
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What is thrust? |
The force that pushes an object forward. |
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What is upthrust? |
The force that pushes an object upwards in a liquid or gas it is also called buoyancy. |
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What is mass? |
Mass is the amount of matter in an object and is measured in kg. |
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What is weight? |
Weight is a force, and is caused by the pull of gravity acting on a mass. It is measured in Newtons. |
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How can forces be represented? |
A force diagram. |
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What causes friction? |
Frictions occurs between two objects because the surfaces are rough and contain bumps and hollows. |
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How do you reduce the impact of air resistance? |
Vehicles are usually streamlined to enable air to flow past them as easily as possible. |
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What is Newton's first law? |
If the forces on an object are balanced, the object will continue doing what it's already doing. If the object is stationary it will stay stationary. If an object is moving it will continue moving at that speed, in the same direction. |
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What is Newton's second law? |
If the forces on an object is unbalanced two things may change. The speed or the direction it is travelling in. |
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How is movement calculated from force? |
force(N) = mass(kg) x acceleration(m/s2) |
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What is Newton's third law? |
If object A exerts a force on object B, then object B exerts an equal but opposite force upon object A. |
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What is speed? |
Speed is a measure of how fast an object moves in a given time. |
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How is velocity different to speed? |
The velocity of an object is the speed and direction in which it is moving. |
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How is speed calculated? |
Speed (m/s) = Distance Travelled (m) / Time (s) |
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What is acceleration? |
The acceleration of an object is a measure of how quickly its velocity changes. |
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How is acceleration calculated? |
acceleration = Change in speed / time taken |
