Unit 1 Flashcards
What is the science of properties, structure, and transformation of matter called?
Chemistry
What is matter?
Anything with mass and takes up space
Can matter be destroyed?
No
What is the Law of Conservation of Mass?
In a chemical reaction, matter is neither created nor destroyed, it is transformed into something else.
Who first came up with the theory of Law of Conservation of Mass?
Lavoisier
What kind of change happens when substances are used up and other compounds are formed to take their place?
Chemical Change
What kind of change occurs when the identity of a matter remains the same but involves change in its state?
Physical Change
Explain a solid.
Having a definite shape and a definite volume. All particles are very close together.
Explain a liquid?
Have an indefinite shape and a definite volume. Particles are not very close together.
Explain a gas.
Have an indefinite shape and an indefinite volume. Particles are very far apart and move freely.
What are some characteristics of physical properties?
Colour, shape, size, texture, mass, volume, and density.
What are some types of changes in physical properties?
Melting, freezing, boiling/vaporization, condensation, ionization, relaxation.
What are some signs of a chemical change? Give some examples.
Odor, change in temperature, change in color, formation of bubbles, solids form. Examples: burning, rusting, rotting, tarnishing, etc.
What is a chemical reaction?
Atoms from 2 substances combine to form new substances.
What type of reaction is this:
2Na + Cl2 –> 2NaCl
Chemical
What is a pure chemical substance consisting of one type of atom, which cannot be broken down further called?
Element
What is a compound?
Definite and constant composition, same properties under a certain set of conditions.
What is a homogenous mixture? Give an example.
Uniform composition and properties throught a sample. It is difficult to see impurities in this mixture. Examples: air, gasoline, salt solutions, etc.
What is a heterogeneous mixture? Give an example.
Non-uniform composition and properties throught a sample. Different components are visibly distinguishable from one another. Example: Water and oil mixed.
What is exponential notation?
Very large or small numbers based on powers of 10.
Which in the exponent and which is the coefficient in: N × 10^n
N: Coefficient
n: Exponent
What is a measurement? Give some examples.
A method in determining a physical quantity. Such as length, time, and temperature.
Why do we need measurements?
So we can quantify time, distance, plan, schedule, risk assessment, quality and precision.
What is accuracy?
How close a measurement is to the true value.
What is precision?
The variation seen when measuring the same part repeatedly with the same device.
What is density?
Physical property, constant at a given temperature.
Why does density change with temperature?
Mass does not change but volume does. Volume increases because molecules move further apart.
Since mass is a constant does density increase or decrease as temperature rises?
Density decreases.
What temperature is waters max density?
4 degrees Celsius
Does the ratio of density of a substance to density of water have units?
No
What device is used to measure specific gravity?
A hydrometer.
Explain what a hydrometer does.
If specific gravity is higher than 1 substance will sink below water. If lower than 1 substance will float on top of water.
What is energy and what are the 2 forms?
Energy is the capacity to do work.
Kinetic energy and potential energy.
What is kinetic energy?
Energy motion possessed by any moving object. Light, heat, mechanical energies. It is proportional to mass and speed.
What is potential energy?
Stored energy. The capacity to move or cause motion due to position. Chemical and nuclear energy.
What is the difference between heat and temperature?
Temperature is the kinetic energy of matter: the faster the molecules move, the higher the temp. Heat is a form of energy: the flow of energy from higher to lower temp source.
What are the 2 units of measurement for heat?
Metric based unit = calorie (cal)
SI based unit = Joule (J)
What is a calorie?
Amount of energy required to increase the temperature of 1g liquid water by 1⁰C
What is a joule?
The amount of energy it takes to exert force of one Newton over a distance of one meter, or heat emitted by one-watt heater for one second.
What is specific heat capacity (c)? And how is it measured?
It is a physical property. The heat required to raise the temperature of 1g of substance by 1⁰C. Measured in cal/g⁰C
What is the equation for specific heat?
Q = mc^T
Q= heat energy (cal)
m= mass (g)
c= specific heat (cal/g⁰C)
^T= change in temperature (T final - T initial)
