Year 10 Chemistry

• In scientific experiments, there are three types of variables: independent, dependent and controlled variables.
• Experimentation in the laboratory has many risks, which can be minimized by completing a risk assessment for any experimental procedures.
• Quantitative data is numerical information about quantities, while qualitative data is descriptive data.
• The collision theory explains what is necessary for chemical reactions to occur.
• Activation energy is the minimum amount of energy that molecules need to possess to have successful or fruitful collisions and form products.
• Reaction Rate is the speed of a chemical reaction, which is the time it takes for the reactants to be converted to products.
• In a reaction where the rate of the reaction is slow, it would take a long amount of time for the reactants to be converted into products.
• In a reaction where the rate of the reaction is fast, it would take a short amount of time for the reactants to be converted into products.
• For a reaction to occur, the particles that are reacting must collide with each other.
• Only some of all the collisions that take place cause a chemical change to happen, these are called 'successful' collisions.
• The greater the number of 'successful' collisions, the faster the rate of a reaction.
• A cube with sides of length 2 cm has an area of one face of 4 cm2 and a total surface area of 24 cm2.
• Some metals are able to form ions of multiple different charges, for example, Copper can form both Cu+ and Cu2+ ions.
• Atoms in the same group have the same number of valence electrons, so they lose/gain the same number of electrons and form ions with the same charge.
• Chemical pollutants are made of atoms, and understanding how they dissolve in water requires knowledge of the atoms that make them up.
• Word equations are useful but they don't show all the information that scientists are interested in.
• Word equations follow a few simple rules: draw an arrow to represent the reaction, write the names of the reactants on the left side of the arrow, write the names of the products on the right side of the arrow, separate different reactants or different products by plus signs, and keep the equation on a single line.
• In an ionic formula, a cation is always followed by an anion, so naming an ionic compound simply lists the name of the cation followed by the name of the anion.
• A chemical equation is a representation of a chemical reaction, and the simplest type of chemical equation uses the names of the substances and is called a word equation.
• Cutting the cube horizontally and vertically results in eight smaller cubes with faces of area 1 cm2 and a total surface area of 48 cm2.
• The collision theory states that there are four factors that affect the rate (speed) of a chemical reaction: temperature, concentration, particle size or surface area, and use of a catalyst.
• If the temperature is increased, the particles have more energy and so move quicker, increasing the rate of reaction.
• Increasing the concentration of reactants increases the number of reactant particles moving together, leading to an increase in the reaction rate.
• Decreasing the particle size of a reactant increases its surface area, leading to a higher chance of collisions and a faster reaction rate.
• A reaction re-arranges atoms to produce one or more new substances.
• Water is a compound of hydrogen and oxygen.
• Drought and human activity can increase salt levels in water.
• The Australian water authorities are required to provide safe drinking water, which involves regular monitoring of water quality.
• In a precipitation reaction, solutions of two soluble ionic compounds are mixed together to form an insoluble precipitate.
• Salts are naturally present in the water system, and during the water cycle, water runs through the soil and rocks, dissolving mineral deposits, and carrying these to lakes, rivers and other water bodies.
• The law of conservation of matter states that in any chemical reaction the number of atoms of each element stays the same.
• Changing the subscripts within formulas would make them completely different substances.
• Hepburn is famous for its mineral water springs that contain high levels of minerals.
• The state of matter of each substance can be shown by a state symbol.
• No atoms are created or destroyed in a chemical reaction, so the number of atoms of each element stays the same.
• Cyanide is a compound of carbon and nitrogen.
• An equation is balanced when there are equal numbers of atoms of each element on either side.
• Many ionic salts are soluble in water, but some ionic compounds are insoluble.
• To show how atoms are re-arranged by a chemical reaction, the equation must always be balanced by changing the coefficients.
• An equation is unbalanced when there are unequal numbers of atoms of an element on either side.