Answer the following question given this paragraph: Density is defined as the mass of an object divided by its volume. Propose a unit of density in terms of the fundamental SI units. Q: Density is defined as the mass of an object divided by its what? Choices: - size - liquid - growth - volume A:
volume
Answer the following question given this paragraph: One type of radioactivity is alpha emission. What is an alpha particle? What happens to an alpha particle after it is emitted from an unstable nucleus?. Q: Alpha emission is a type of what? Choices: - radiation - heat - light - radioactivity A:
radioactivity
Q: Answer the following question given this paragraph: Methane has a three-dimensional, tetrahedral structure. Q: What structure does methane have? Choices: - two dimensional oxyhedra - two dimensional tetrahedra - three dimensional oxyhedra - three dimensional tetrahedra A:
A: three dimensional tetrahedra
Question: Answer the following question given this paragraph: A chemical reaction occurs when some substances change chemically to other substances. Chemical reactions are represented by chemical equations. Q: What occurs when some substances change chemically to other substances? Choices: - toxic reaction - spontaneous mutation - hormonal reaction - chemical reaction A:
Answer: chemical reaction
*Question*
Answer the following question given this paragraph: Based on their knowledge of subatomic particles, scientists have developed a theory called the standard model to explain all the matter in the universe and how it is held together. The model includes only the fundamental particles in the Table above . No other particles are needed to explain all kinds of matter. According to the model, all known matter consists of quarks and leptons that interact by exchanging bosons, which transmit fundamental forces. The standard model is a good theory because all of its predictions have been verified by experimental data. However, the model doesn't explain everything, including the force of gravity and why matter has mass. Scientists continue to search for evidence that will allow them to explain these aspects of force and matter as well. You can learn much more about the standard model at the URL below. Click on "the standard model" and follow the sequence titled "What is fundamental?". Q: What is the theory scientists use to explain the matter in the universe and how it's held together? Choices: - specific model - original model - organic model - standard model A:
**Answer**
standard model
Answer the following question given this paragraph: Amines are capable of hydrogen bonding though their boiling points are generally a bit lower than the corresponding alcohol. Methylamine and ethylamine are gases at room temperature, while larger amines are liquids. As with other organic compounds that form hydrogen bonds, water solubility is reflected in the length of the carbon chains. Smaller amines are soluble, while larger ones are less soluble. Q: As with other organic compounds that form hydrogen bonds, water solubility of amines is reflected in the length of what? Choices: - hydrocarbon bonds - complex carbohydrates - nuclei chains - carbon chains A:
carbon chains