Answer the following question given this paragraph: Each element has its own square in the periodic table. The square contains the chemical symbol for the element, the atomic number, and the atomic weight . The atomic weight of an element is a weighted average of its isotopes. Q: The periodic table of elements is divided into what? Choices: - patterns - spheres - groups - squares A:
squares
(Question)
Answer the following question given this paragraph: Birds need a light-weight body in order to stay aloft. Even so, flying is hard work, and flight muscles need a constant supply of oxygen- and nutrient-rich blood. The organ systems of birds are adapted to meet these needs. Q: Why do birds need a light-weight body? Choices: - for cooling - water flotation - food shortages - to stay aloft A:
(Answer)
to stay aloft
Ques: Answer the following question given this paragraph: Molecular orbital theory describes the distribution of electrons in molecules in much the same way that the distribution of electrons in atoms is described using atomic orbitals. Using quantum mechanics, the behavior of an electron in a molecule is still described by a wave function, , analogous to the behavior in an atom. Just like electrons around isolated atoms, electrons around atoms in molecules are limited to discrete (quantized) energies. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital (2). Like an atomic orbital, a molecular orbital is full when it contains two electrons with opposite spin. We will consider the molecular orbitals in molecules composed of two identical atoms (H2 or Cl2, for example). Such molecules are called homonuclear diatomic molecules. In these diatomic molecules, several types of molecular orbitals occur. The mathematical process of combining atomic orbitals to generate molecular orbitals is called the linear combination of atomic orbitals (LCAO). The wave function describes the wavelike properties of an electron. Molecular orbitals are combinations of atomic orbital wave functions. Combining waves can lead to constructive interference, in which peaks line up with peaks, or destructive interference, in which peaks line up with troughs. Q: Which theory describes the distribution of electrons in molecules in much the same way that the distribution of electrons in atoms is described using atomic orbitals? Choices: - molecular distribution theory - atomic orbital theory - atomic distribution theory - molecular orbital theory A:
Ans: molecular orbital theory
(Q).
Answer the following question given this paragraph: Primates called prosimians are generally smaller. There are also far fewer of them. Prosimians include lemurs, such as the mouse lemur in Figure above , and lorises. Prosimians are thought to be more similar to the earliest primates. Q: Prosimians are thought to be more similar to the earliest of these? Choices: - rodents - fish - insects - primates A:
(A).
primates
Ques:Answer the following question given this paragraph: Electron Microscopes In contrast to light microscopes, electron microscopes use a beam of electrons instead of a beam of light. Not only does this allow for higher magnification and, thus, more detail (Figure 3.3), it also provides higher resolving power. Preparation of a specimen for viewing under an electron microscope will kill it; therefore, live cells cannot be viewed using this type of microscopy. In addition, the electron beam moves best in a vacuum, making it impossible to view living materials. In a scanning electron microscope, a beam of electrons moves back and forth across a cell's surface, rendering the details of cell surface characteristics by reflection. Cells and other structures are usually coated with a metal like gold. In a transmission electron microscope, the electron beam is transmitted through the cell and provides details of a cell's internal structures. As you might imagine, electron microscopes are significantly more bulky and expensive than are light microscopes. Q: What powerful microscopes use a beam of subatomic particles instead of a beam of light? Choices: - complex microscopes - scientific microscopes - nuclear microscopes - electron microscopes A:

Ans:electron microscopes
Ques: Answer the following question given this paragraph: Q: What occurs when there is little to no rain in a period of time? Choices: - pollution - hurricanes - floods - droughts A:
Ans:
droughts