Nature of Science
The variable that is affected by the independent variable, and changes at the end of an experiment.
What is a dependent variable?
A property of substances that describes how it reacts to other substances and changes its chemical identity as a result.
What is a chemical property?
A property of a substance that can be observed or measured without changing the chemical identity of the substance.
What is a physical property?
Atomic nuclei splits apart into two daughter nucleus.
What is nuclear fission?
Based upon the idea that all matter is made of particles that are in constant motion.
What is the Kinetic Theory of Gases?
Pseudoscience includes beliefs, theories, or practices that have been or are considered scientific, but have no basis in scientific fact.
What is pseudoscience?
The smallest unit of an element that demonstrates the properties of that element
What is an atom?
A positively charged subatomic particle that has a mass of approximately one atomic mass unit
What is a proton?
Displays the state of a substance at various pressures and temperatures and the places where equilibria exist between phases.
What is a phase diagram?
-Typically when temperature increases, volume increases (with constant pressure), pressure increases (with constant volume) and density decreases (with constant pressure).
What is the relationship between volume, pressure, temperature and density?
Is a description of an observed phenomenon. It doesn't explain why the phenomenon exists or what causes it. They are always accepted to be true and universal.
What is a scientific law?
Made up of different particles that are not uniformly distributed.
What is a heterogenous mixture?
Made up of different particles that are uniformly distributed.
What is a homogeneous mixture/solution?
Electric and magnetic fields travel through space as transverse waves at right angles.
What is the electromagnetic field?
The particles of a gas are considered to be small with insignificant volume.
No attractive or repulsive forces exist between the particles.
The motion of the particles in a gas is rapid, constant, and random.
All collisions between particles in a gas are elastic.
The average kinetic energy of a gas is proportional to the absolute temperature.
What are the assumptions of Kinetic Theory?
A method of expressing really big or really small numbers.
What is scientific notation?
Low melting points
Tend to be gases or liquids
Made of 2 nonmetals
Have covalent bonds
Poor conductors of heat or electricity
What are the physical properties of covalent compounds?
-Step 1| Identify the symbol for the element and its number of valence electrons using the periodic table.
-Step 2| Place the corresponding number of electron dots around the symbol. Imagine that the symbol has four sides: top, right, bottom, and left. Begin by assigning one dot per side, moving clockwise around the symbol. Then, if there are still more dots to assign, start adding a second dot to each side until all of the valence electrons have been accounted for.
What are the steps for drawing an electron dot structure?
1. Requires energy to be present as a reactant.
2. Energy is absorbed by the change taking place.
3. You will see energy added to the reactants side (left) of an equation
What is an endothermic reaction?
states that for a given mass of a gas at a constant temperature, the volume of the gas varies inversely (indirectly) with pressure.
If volume goes down the pressure goes up.
P1V1 = P2V2
What is Boyle's Law?
Observing and asking questions
Inferring & forming a hypothesis
Designing a controlled experiment
What are the steps of the scientific method?
Step 1 | Find the sign of the charge by determining whether protons outnumber electrons or electrons outnumber protons in the ion.
Step 2 | Find the magnitude of the charge by determining the difference between the number of protons and electrons in the ion.
What are the steps for finding the charge of an ion?
- the elements in group 7A on the periodic table
-Highly reactive nonmetals
-Gain one electron to complete octet and have –1 charge as ions
What are the properties of halogens?
-Chemical reactions occur because of instability in electron configurations and involve the interactions of electrons between different substances such that they become more stable (like a noble gas).
-Nuclear reactions occur because of instability in the nuclear geometry of an atom and involve the splitting of a nuclei (nuclear fission) or the coming together of nuclei (nuclear fusion) such that the nucleus becomes more stable.
What is the difference between chemical and nuclear reactions?
- states that at a constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of the component gases.
- PT = P1 + P2 + P3
What is Dalton's Law of Partial Pressures?