Answer the following question given this paragraph: An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. Q: What is the the force of attraction that holds together ions? Choices: - covalent bond - soluble bond - magnetic bond - ionic bond A:
ionic bond
Answer the following question given this paragraph: The central nervous includes the brain and spinal cord. The brain is the control center of the nervous system. It controls virtually all mental and physical processes. The spinal cord is a long, thin bundle of nervous tissue that passes messages from the body to the brain and from the brain to the body. Q: The brain and spinal cord are part of what system, which serves as a control center? Choices: - primary nervous system - active nervous system - large nervous system - central nervous system A:
central nervous system
Q: Answer the following question given this paragraph: There are two common ways to measure pH. When only an approximate pH value is needed, an inexpensive test involves the use of acid-base indicators , which change color based on the relative acidity of the solution. One type of common indicator is litmus paper. For example, if a piece of litmus paper is dipped into an acidic solution (pH below ~4.5), it will turn red, and dipping it into a basic solution (pH above ~8.5) will turn it blue. Solutions of intermediate pH will result in various shades of purple. Because different indicators change color at different pH values, the use of multiple indicators can generally narrow down the possible pH of a solution to a range of about 0.5-1 pH units. Figure below shows the colors exhibited by various indicators at different pH values. Q: How does litmus paper indicate the ph value of a solution? Choices: - by texture - by shape - by smell - by color A:
A: by color
Question: Answer the following question given this paragraph: When an ionic compound dissociates in water, water molecules surround each ion and separate it from the rest of the solid. Each ion goes its own way in solution. Saylor URL: http://www. saylor. org/books. Q: When an ionic compound dissociates in water, water molecules surround each ion and separate it from the rest of the what? Choices: - electron shell - mixture - gas - solid A:
Answer: solid
*Question*
Answer the following question given this paragraph: A: Most ocean waves are caused by wind blowing across the water. Moving air molecules transfer some of their energy to molecules of ocean water. The energy travels across the surface of the water in waves. The stronger the winds are blowing, the larger the waves are and the more energy they have. Q: Most ocean waves are caused by what? Choices: - radiation - animals - gravity - wind A:
**Answer**
wind
Q: Answer the following question given this paragraph: 4. Molecular crystals -- Molecular crystals typically consist of molecules at the lattice points of the crystal, held together by relatively weak intermolecular forces (see Figure below ). The intermolecular forces may be dispersion forces in the case of nonpolar crystals, or dipole-dipole forces in the case of polar crystals. Some molecular crystals, such as ice, have molecules held together by hydrogen bonds. When one of the noble gases is cooled and solidified, the lattice points are individual atoms rather than molecules. In all cases, the intermolecular forces holding the particles together are far weaker than either ionic or covalent bonds. As a result, the melting and boiling points of molecular crystals are much lower. Lacking ions or free electrons, molecular crystals are poor electrical conductors. Q: What crystals consist of molecules at the lattice points of the crystal, held together by relatively weak intermolecular forces? Choices: - quartz crystals - salt crystals - healing crystals - molecular crystals A:
A: molecular crystals