When cool, dense air from over the water flows inland, it's called a ____. a. land breeze c. jet stream b. polar easterly d. sea breeze
We can determine the velocity of a wave when given the _______ and the wavelength. (2 points) frequency amplitude crest equilibrium
Which is the first step in the dissolving process? A.) The solute becomes like the solvent. B.) The solute molecules are carried into the solution. C.) The solvent molecules surround the solute particles. D.) The solvent molecules are attracted to particles at the surface of the solute.
One characteristic of a scientific theory is that _______ a. it can never be proved b. it can be proved c. it cannot be modified d. it summarizes a set of observations
What are the properties of elements related to? A) the number of electrons that fill the outer shell B) an element's symbol C) the total number of electrons D) the average atomic mass
There are three main types of mixtures. Which is a homogeneous mixture? Salt water contains small particles that have moved, so they are evenly spread through the mixture. Paint is composed of many colored particles that separate from the rest of the mixture when left in the can for a long time. Shaving cream is a mixture that contains small- to medium-sized particles suspended in foam.
The amount of heat involved in the synthesis of 1 mole of a compound from its elements with all substances in their standard states at 25 degrees celcius is called
The atmosphere's variable gases that most influence the greenhouse effect are _____. nitrogen and oxygen argon and carbon dioxide carbon dioxide and water vapor water vapor and ozone
Hydrogen fuel cells burn with _______ and produce _______. a. water, oxygen b. oxygen, water c. carbon dioxide, oxygen d. oxygen, carbon dioxide
In water, HNO3 produces H+ ions. Which is the name for HNO3 in an aqueous solution? hydrogen nitrate nitric acid saltpetre nitrous acid
Which of the following best describes the electron cloud model? A. It shows that electrons usually carry a negative charge. B. It shows that electrons remain in high-energy subshells. C. It shows that electrons move quickly in circular orbits. D. It shows that the electrons within an atom do not have sharp boundaries.
Which change results in the formation of different substances? (1) burning of propane (2) melting of NaCl (s) (3) deposition of CO2(g) (4) solidification of water
Which of the following changes has a decrease in entropy? . A.hg N2O4 (g) 2NO2 (g) B.3O2 (g) + 2KCl (s) 2KClO3 (s) C.C2H5OH (l) + 3O2 (g) 2CO2 (g) + 3H2O (g) D.H2O (l) H2O (g)
Which statement correctly describes the relationship between reactant and yield? The actual yield is calculated from the amount of the excess reactant present. The actual yield is calculated from the amount of the limiting reactant present. The theoretical yield is calculated from the amount of the excess reactant present. The theoretical yield is calculated from the amount of the limiting reactant present.
Write the chemical symbols for three different atoms or atomic anions with 17 electrons. site:answers..com
If a substance reacts with oxygen, the chemical reaction is most likely a combustion reaction. decomposition reaction. single replacement reaction. double replacement reaction.
Which of the following is not a result of air pollution? A. Smog B. Breathing problems C. Global warming D. Soil erosion
In a nuclear reaction, mass must be lost to produce energy. Please select the best answer from the choices provided T F
From the following observations, identify the base. . 1. a solution conducts electricity and feels slippery. 2. a solution conducts electricity and reacts with metal. 3. a solution is sour and produces hydrogen gas. 4. a solution conducts electricity and forms salts
Calculate the ph of the resulting solution if 25.0 ml of 0.250 m hcl(aq) is added to(b) 35.0 ml of 0.300 m naoh(aq).
Which type of graph is best for analyzing quantitative dependent and independent variables? a. line graph b. pie graph c. bar graph d. surface graph
H2, N2, O2 molecules. . . A)must be polar. must be nonpolar. . B)can be polar or nonpolar depending on geometric . C)configuration. . D)indeterminate