Question | Answer |
Physical Properties | a property that can be observed without changing the identity of the substance |
Physical Changes | occurs when matter changes its property by not in a chemical nature: texture, shape,, size, color, odor, volume, mass, weight, density |
Chemical properties | the way a substance may change or react to form another substance-heat combustion, re-activity to water, pH, oxidation, flammability, re-activity to other chemicals |
Chemical changes | changes matter undergoes when it becomes new or different matter |
Boiling point | physical property- the point in which the property is from liquid to gas |
Ability to rust | chemical property- reacts with oxygen to produce rust |
Melting point | physical property- the point in which the property is liquid form from a solid or gas state |
Brittleness | physical property- the property where it can break without deforming or shredding the object |
Reactivity with vinegar | Chemical property- the ability to change the form of the property |
elasticity | physical property- the ability to be stretched or not |
flammability | Chemical property- the ability to burn |
denisity | physical property- the compactness of the substance |
transparency | physical property- the property of letting light pass through something |
ductility | physical property- the property to be able to be flatten |
sublimation | when anything solid turns into a gas with out being liquid first |
combustible | ability to catch fire and burn |
what are the five indicators of chemical reaction | emission of light or heat, formation of gas, formation of precipitate, color change, emission of odor |
color change | when the property change from gray to brown rust- ex rust |
precicipitate | a solid substance that forms as a result of reaction between chemicals in two liquid- ex. baking soda and vinegar |
gas production | when two substances are mixed and forms gas. ex antacid and stomach fluid |
temperature change | most reactions involve this. from a flame, or concrete before hardening ex. fireworks |
change in characteristic | properties are changed by light or odor. ex. light stick |
what are the five types of chemical reactions | synthesis, decomposition, single replacement, double replacement, combustion |
synthesis | two or more elements or compounds combine to make a more complex substance |
synthesis example | a + b -> AB |
decomposition definition | compound breaks down into simpler substance |
decomposition example | AB -> A + B |
single replacement definition | occurs when one element replaces another one in a compound |
single replacement example | AB + C -> AC + B |
double replacement definition | occurs when different atoms in two different compounds trade places |
double replacement example | AB + CD -> AC + BD |
combustion definition | one reactant is always oxygen and another reactant often contains carbon and hydrogen. the carbon and hydrogen atoms combine with oxygen, producing |
combustion example | C + O2-> CO2 + heat |
what is the speed of reaction called | Rate of reaction |
What is Activation energy | The minimum amount of energy needed for particles to react and is different for each reaction |
What are 4 factors affect the rate of reaction | Increase temperature
increased concentration of dissolved reacts or pressure of gas
in teased surface area
use a catalyst |
Why does a reaction proceed faster when the react ants have greater surface area | more particles are available to collide and react when the surface area is greater Each time a large piece is broken, more surface area is exposed |
Concentration | A number of particles present in a certain volume. Higher means more can collide |
Catalyst | Is a substance that increases the rate of a chemical reaction without being consumed in the reaction |
Inhibitor | Is a substance that slows or prevents a reaction |
Why must chemical reactions be balanced | |
To shine or not to shine what are the catalyst | Salt acted as a catalyst to help speed up the chemical reaction |
What does lower activation energy mean | More coliseum between particles have sufficient energy to react |
Why must chemical reactions be balanced | The law of conservation says that matter is neither created nor destroyed during a chemical reaction so the number of atoms of each element must be the same on both sides of the equation |
What are reactants | Are the substance at the beginning of a he iCal reaction |
Product | The substance afterit is combined by a chemalreaction |
What is a coefficient | Indicates how many molecules take place in the reaction |
If a chemical equation does not obey the law of conservation of mass the equation is said to be | Not to balanced |
Who was Afntoine Lavosier | Scientist who came up with the law of conservation of mass helped construction of periodic table , named On and H |
What is the law of conservation | Mass is neither created nor destroyed during chemical reaction or physical reaction the bond between atoms in the reaction so all chemical equations must be balanced |
What is bond energy | The energy associated with bonds breaking |
What is photosynthesis | It is an endothermic reaction that absorbs energy from the sun to turn carvon dioxide and water into oxygen and glucose |
Endothermic process | A change (chemical reaction) that requires (or absorbs) heat, energy is taken in but not necessary given out |
How can you determine if the reaction is endothermic | The temperature of the reaction mixture decrease |
Exeothermic process | A change (a chemical reaction) that releases heat-energy is released as heat and light. More energy is given out than taken in |
Example of Exothermic | Burning fossil fuels, combustion, salt ando water |
Examples of endothermic | Photosynthesis, a edict acid and sodium, |
Why were catalyst converters developed | To help cars and trucks or machines move |
What part of Silicon makes properties important in electronics | 98%per |
How is chemical reaction important in indusrty | To make things move, light up, heat up, pick things up,machine things |