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What element has eight protons and nine neutrons?

The atom is the smallest unit that is able to retain all the properties of a chemical element. It contains three primary subatomic particles, including protons, neutrons and electrons. In the periodic table, an element is represented by its atomic symbol, atomic number and mass number. The atoms of different chemical elements possess a unique atomic number, which is equivalent to the number of protons present in the atomic nucleus. In a neutral atom, the atomic number is also equal to the number of electrons. The mass number, meanwhile, indicates the sum of the protons and neutrons in the nucl..

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What is minute ventilation?

A person's minute ventilation can increase or decrease based on whether or not he is stressed, exercising or participating in other strenuous activities. An increase in ventilation is the result of an increase in a demand for oxygen combined with an increase in the production of carbon dioxide. A decrease is the result of a decrease in oxygen demand and carbon dioxide production.

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What is the purpose of a theory?

The scientific method is a process through which scientists attempt to create an accurate understanding and representation of the world. Theories and hypotheses are created as an attempt to explain scientific observations and are later tested through experimentation. It is commonly said that scientific theories can never be proven, only disproved, thereby allowing the possibility for new and more accurate theories to be created.

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Why do organisms need to carry out the process of respiration?

The most efficient form of respiration occurs when oxygen is available to oxidize the glucose. Respiration in the presence of oxygen is called aerobic respiration. Cells use this oxygen to change molecules of glucose into carbon dioxide, water and ATP. The carbon dioxide and water are waste products that are flushed from the system, whereas the ATP is the primary energy source used by the organism. This process is why animals need to breathe in oxygen and exhale carbon dioxide.\nAerobic respiration consists of four distinct stages: glycolysis, in which the initial decomposition of glucose occu..

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When do you need to use Ohm's law?

Resistance and resistors limit the amount of current traveling through a circuit, therefore establishing certain levels of voltage. Most appliances need a certain amount of voltage to properly operate, and Ohm's law helps you maximize the efficiency of the machine by not producing excess voltage. Ohm's law mainly calculates resistance, but it may also be rearranged and used to calculate the voltage or current a given resistance produces.

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What are the two main sources of genetic variation?

Some mutations, which affect all cells in an organism, are inherited from a parent. Other mutations develop during an organism's life and occur in only some cells. Mutations are not always harmful. For instance, although the disease sickle cell anemia is caused by a mutation, that modified DNA also helps prevent malaria in some people.\nSexual reproduction causes genetic variation because of three factors. During the cell division that produces eggs and sperm, genetic material is exchanged. When these sex cells are formed, chromosomes are assorted by chance. In addition, a random egg and ..

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How often do volcanoes occur?

Many volcanic eruptions last for hours, though some may go as long as days or weeks. Even when the eruption stops, it is still considered active. It takes approximately 10 years after an initial eruption for the volcanic eruption to be considered completed, though it could take more than 100 years for the volcano to cool. Volcanoes typically have a life span of several thousand years. During an eruption, volcanoes release ash first, followed by lava.

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What are some water conservation methods?

It is critical to conserve water in arid areas, such as the Southwest, and water agencies are continually searching for new water resources to supply the water needs of growing communities. Cities and farms work together to find methods to improve the usage of existing supplies through innovative management of water resources and the use of new technology.\nHomeowners can conserve water during hot summer months by aerating lawns, and using a combination of compost and mulch on flower beds to prevent rapid evaporation. Gray water systems can be installed to collect waste water from bathtubs, wa..

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How do you read Vernier micrometer caliper scales?

Address zero correctionMake sure that fully closed jaws give a reading of zero on the Vernier micrometer caliper. If the instrument cannot be corrected using special wrenches to give a zero reading on full closure, you must add or subtract any error from the final reading when measuring an object.Position the object to be measured within the caliper’s jawsPosition the object between the caliper’s fixed and movable jaws. Lightly close down on the object using the instrument’s precise, uniform screw to close the movable jaw.Calculate the final readingRead the measurement on the main scale ..

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How do volcanoes affect the lithosphere?

A volcanic eruption is a process by which molten rocks and hot gases are pushed through the Earth’s crust from a volcanic mountain. Volcanic eruptions usually occur at the boundaries of tectonic plates. The plates are either pulled apart or together, which then break and change the state of the layers. Magma, which is the mixture of molten rocks and hot dissolved gases, moves to the surface of the earth and is called lava.\nThe crust and the top layer of the mantle is referred to as the lithosphere. In the lithosphere, volcanic eruptions can form new rocks or destroy existing organisms. Alth..

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