Answer the following question given this paragraph: In the Bohr model, the atom is viewed as a densely packed nucleus comprised of neutrons and protons that is surrounded by electrons at fixed distances, which correspond to specific energy levels. However, the quantum model showed that the distances between electrons and the nucleus are not really fixed. Due to their wave-like nature, we cannot pinpoint the exact location of an electron that is in motion, but we can determine the probability that a given electron will be in a particular region in three-dimensional space. Schrdinger's equations are used to determine the position of a specific electron with respect to a nearby nucleus. The region in space in which an electron is most likely to be found is referred to as an orbital . Q: Which atomic model shows that the distances of electrons from the nucleus is not a fixed value? Choices: - the electron model - the distance model - the equivocation model - the quantum model A:
the quantum model
(Question)
Answer the following question given this paragraph: Q: What is the most effective color in interrupting the nighttime portion of the photoperiod? Choices: - yellow - white light - blue light - red light A:
(Answer)
red light
Ques: Answer the following question given this paragraph: Rutherford's experiment showed that the vast majority of the mass of an atom is concentrated in its nucleus, which is composed of protons and neutrons. The mass of an electron is very small compared to the mass of a neutron or proton, so the electrons in an element do not contribute much to the total mass. The mass number is defined as the total number of protons and neutrons in an atom. Remember that both protons and neutrons have a mass of approximately 1 amu. Knowing the mass number and the atomic number of an atom therefore allows you to determine the number of neutrons present in that atom by subtraction:. Q: According to rutherford, where is the vast majority of the mass of an atom located? Choices: - the cytoplasm - the shell - the electrons - the nucleus A:
Ans: the nucleus
(Q).
Answer the following question given this paragraph: After an infection has been brought under control, most cytotoxic T cells die off. However, a few remain as memory cells. If the same pathogen enters the body again, the memory cells mount a rapid immune response. They quickly produce many copies of cytotoxic T cells specific to the antigen of that pathogen. Q: After an infection has been brought under control and most cytotoxic t cells die off, a few remain as what? Choices: - b cells - natural killer cells - control cells - memory cells A:
(A).
memory cells
Ques:Answer the following question given this paragraph: Many Earth scientists collect data in the field, called field work . The data may be from observations or measurements. The scientists may create a geological map of the area. They might write detailed descriptions of the rocks and their relationships. They may collect samples to analyze in the lab. They may do a combination of all of these! Earth science laboratories contain high-tech equipment. That equipment can reveal the chemistry or age of a rock sample. Geologists do field work to look for resources. They may study a region for environmental cleanup. There are many other reasons for going in the field. One common reason is just to understand the region better. Q: The scientific process of collecting data outside the lab (in the "wild") is known as what kind of work? Choices: - scientific investigation - experimentation - track work - field work A:

Ans:field work
Ques:Answer the following question given this paragraph: Some chemical reactions can occur in only one direction. These reactions are called irreversible reactions. The reactants can change to the products, but the products cannot change back to the reactants. These reactions are like making a cake. The ingredients of a cakesuch as eggs and flourare the reactants. They are mixed together and baked to form the cake, which is the product (see Figure below ). The cake can't be "unbaked" and "unmixed" to change it back to the raw eggs, flour, and other ingredients. So making a cake is irreversible. Q: What are reactions that can occur only in one direction called? Choices: - permanent - instantaneous - critical - irreversible A:

Ans:
irreversible