Semester 1 Final (+Q1 Final) Flashcards
What are the signs of a Chemical Change? Examples.
Formation of gas, temperature change, color change, formation of a precipitate (solid), odor change. Burn wood, bake a cake, rust iron, etc.
What are some examples of a Physical Change?
Ice melting, paper crumpling, boiling water, mixing sand and water, etc.
What is cohesion? Explain using water.
The sticking together of particles of the same substance. Water is attracted to water.
What is adhesion? Explain using water.
The attraction between particles of different substances. Water is attracted to other substances.
Mixture
A substance made up of two or more different chemical substances which are not chemically bonded.
Solute
The substance being dissolved
Solvent
The dissolving medium
Solution
A homogeneous mixture consisting of a solute dissolved into a solvent
Exothermic Reactions
More energy is released than absorbed. Releases heat, causing an increase in temperature of the reaction mixture.
Endothermic Reactions
More energy is absorbed than released. Accompanied by a decrease in temperature of the reaction mixture.
Law of Conservation of Matter
Matter is never created or destroyed. So, the same amount of matter exists both before and after the chemical reaction took place.
Reactants
The original substance or substances in a chemical reaction
Products
The substance or substances that form in a chemical reaction
What was Dmitri Mendeleev’s importance to chemistry?
He created the periodic table. He devised the periodic classification of the chemical elements, in which the elements were arranged in order of increasing atomic weight.
Atomic Mass. Where is it located?
The number of protons and neutrons in the nucleus. Bottom of the element square.
What are the six elements that make up 98% of life?
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, and Sulfur
How many electrons can each level of a bohr model hold?
1st EnergyLevel = 2. 2nd Energy Level = 8. 3rd Energy Level = 18
What are the energy changes that accompany each state?
Solid to liquid = lose energy. Solid to gas = lose energy. Liquid to gas = lose energy. Gas to solid = gain energy. Liquid to solid = gain energy. Gas to liquid = gain energy.
Heat
a flow of energy from an object at a higher temperature to an object at a lower temperature.
Temperature
a measurement of the average kinetic energy of particles in an object
Kinetic Energy
The energy of an object or system’s particles in motion
Potential Energy
Stored energy in any object or system
Thermal Energy
The energy contained within a system that is responsible for its temperature.
Electrical Energy
The power an atom’s charged particles have to cause an action or move an object
Mechanical Energy
The energy of either an object in motion or the energy that is stored in objects by their position. The sum of kinetic and potential energy.
Chemical Energy
Energy stored in the bonds of atoms and molecules.
Electromagnetic Energy
Radiant energy that travels in waves at the speed of light.
Law of Conservation of Energy
Energy is never created nor destroyed.
What are prokaryotic cells?
No nucleus. Small and simple. No organelles. Are very abundant. All are unicellular. Cells have a sticky capsule. All cells have cell walls. Live in a wide variety of environments. All are bacteria. Have ribosomes, DNA, cytoplasm, and cell membrane. Some have flagella.