Answer the following question given this paragraph: Concentration is the number of particles of a substance in a given volume. When the concentration of reactants is higher, the reaction rate is faster. At higher concentrations, particles of reactants are crowded closer together, so they are more likely to collide and react. Did you ever see a sign like the one in Figure below ? You might see it where someone is using a tank of pure oxygen for a breathing problem. The greater concentration of oxygen in the air makes combustion rapid if a fire starts burning. Q: The number of particles of a substance in a given volume is known as? Choices: - frequency - range - mass - concentration A:
concentration
Answer the following question given this paragraph: Earth is a giant magnet with north and south magnetic poles and a magnetic field called the magnetosphere. Evidence in rocks shows that Earth's magnetic poles switched positions hundreds of times in the past. Scientists think that Earth's magnetic field is caused by the movement of charged particles through molten metals in the outer core. Q: The magnet field of earth is called what? Choices: - atmosphere - troposphere - ionosphere - magnetosphere A:
magnetosphere
Q: Answer the following question given this paragraph: Two traits are used to define the mammal class. They are fur or hair and mammary glands in females. Q: What types of glands do only female mammals have? Choices: - pituitary - thyroid - respiratory - mammary A:
A: mammary
Question: Answer the following question given this paragraph: The first species to colonize a disturbed area such as this are called pioneer species (see Figure below ). They change the environment and pave the way for other species to come into the area. Pioneer species are likely to include bacteria and lichens that can live on bare rock. Along with wind and water, they help weather the rock and form soil. Once soil begins to form, plants can move in. At first, the plants include grasses and other species that can grow in thin, poor soil. As more plants grow and die, organic matter is added to the soil. This improves the soil and helps it hold water. The improved soil allows shrubs and trees to move into the area. Q: What are species that are first to colonize a disturbed area called? Choices: - novel species - exploratory species - brave species - pioneer species A:
Answer: pioneer species
*Question*
Answer the following question given this paragraph: Mass can be destroyed to release energy. We do not ordinarily notice the increase or decrease in mass of an object because the change in mass is so small for a large increase in energy. The relativistic work-energy theorem is W net = E E 0 = mc 2 mc 2 = 1mc 2 . Relativistically,. Q: Mass can be destroyed to release what? Choices: - acceleration - mass - velocity - energy A:
**Answer**
energy
(Question)
Answer the following question given this paragraph: The protist wraps around its prey, which is usually bacteria. Q: What is usually the prey of a protist? Choices: - pathogens - algae - proteins - bacteria A:
(Answer)
bacteria