Matter & Chemical Change Flashcards
What is the Law of Conservation of Mass?
- Matter is not created or destroyed, only rearranged
- The total mass of the products must be equal to the total mass of the reactants
- Discovered by Antoine Laurent Lavoisier
What’s the difference between exothermic and endothermic reactions?
Exothermic (exiting) reactions release energy while endothermic (enters) reactions require or absorb energy
What does a manipulated variable means in an experiment?
The variable that is changed
What are the four factors that can increase a chemical reaction?
Change the temperature (heat up) Add a catalyst (enzyme) Increase the surface area (break into smaller pieces) Increase the concentration (amount) of reactants
What are the three types of reactions with oxygen?
Combustion: when oxygen and another substance react together to produce a new substance and energy Corrosion: when oxygen in the atmosphere reacts with a metal producing rust Cellular Respiration: breathing of your cells
What kind of air conditions has the lowest moisture? (What kind of air conditions would make corrosion [rust] occur slower?)
Cold and dry
What’s the difference between a physical and chemical change?
A physical change is a change in appearance or state of a substance [particles stay the same], while a chemical change is when a new substance is made
What’s the difference between reactants and products in a chemical reaction?
Products is what is produced from the reaction, the reactants are the substances that react together to make the product.
Where do you find the charges on an element in the periodic table?
Found at the top right corner of an element
Be able to read a word equation
Test will take the word sentence and break it down smaller. Ex.
Metal + Non-metal = ________
Ionic compound
Non-metal + Non-metal = ________
Molecular compound
What’s the Roman Numeral means on an ionic compound
If more than one charge on metal, tells you the charge you’re using
How do you calculate the number of neutrons in an element?
Subtract the atomic number from the mass number
Where are metals and non-metals found on a periodic table?
Left of staircase: Metals On Staircase: Metalloid Right of staircase: Non-metals
What are the four indicators of a chemical change?
-Change in odour -Heat release/absorption -Formation of gas or solid\ -Change in colour
What is the most recent theory of matter is and what does it say?
Quantum Mechanics: the electrons are in a cloud around the nucleus (moving all around)
Know the structure of an atom and how to compare it to a solar system
The Sun= nucleus (protons & neutrons) The Planets= electrons
Be able to pick out some examples of a pure substance Ex. ‘water’ or ‘distilled water’ -> Mixture or pure substance? Ex. ‘air’ -> Mixture or pure substance?
Pure substances are elements or compounds Ex. They say ‘water’ and ‘distilled water’ The distilled (filtered) water is the pure substance because if its just water, it could have particles of dirt in it. The water is a mixture. Ex. They say ‘air’ It’s not a pure substance because it could have dust, skin particles. It’s a mixture.
What do you do immediately do should you come in contact with a harmful chemical during a science experiment?
Wash it immediately, then seek help.
How do you name ionic compounds? Ex: NaCL
- Write down the name of the metal ion first – Sodium 2. Write down the name of the non-metal ion second but change the ending to “ide” – Chloride 3. Therefore NaCl = Sodium Chloride * Sometimes a metal ion has more than one charge so you need to use Roman numerals to indicate the one you are using. Example: Copper(II) Chloride has copper with a 2+
How do you write an ionic formula? Ex: Magnesium Chloride
- Write down metal ion first with its charge – Mg2+ 2. Write down the non-metal ion next with its charge – Mg2+Cl- 3. Keep adding either metal or non-metal ions until the charges balance. They must equal zero – Mg2+Cl-Cl- 4. Count the number of ions of each element and put the number as a subscript to the right of the ion symbol and remove the charge. Remember the number 1 is invisible 5. Therefore Mg2+Cl-Cl- = MgCl2
How do you name molecular compounds? Ex: OCl2
- Write down the element name for the first element – Oxygen 2. If there is more than one atom of an element, you need to add the appropriate prefix (tri, penta, etc.) 3. Write the name of the second element with the “ide” ending and include the prefix – dichloride 4. Therefore OCl2 = Oxygen dichloride
Name the 10 prefixes for molecular compounds
MDTTPHHOND [maggie’s dad tried to put his hairy opening near daryl] Mono (don’t use for first element) Di Tri Tetra Penta Hexa Octa Nona Deca

