Answer: It wouldn't be D...Go from there All the other could have several changes ...but I don't which would have the most.
Explanation:
Matter is defined as anything that occupies space and has mass, and it is all around us. Solids and liquids are more obviously matter: We can see that they take up space, and their weight tells us that they have mass. Gases are also matter; if gases did not take up space, a balloon would stay collapsed rather than inflate when filled with gas.
Solids, liquids, and gases are the three states of matter commonly found on earth (Figure 1). A solid is rigid and possesses a definite shape. A liquid flows and takes the shape of a container, except that it forms a flat or slightly curved upper surface when acted upon by gravity. (In zero gravity, liquids assume a spherical shape.) Both liquid and solid samples have volumes that are very nearly independent of pressure. A gas takes both the shape and volume of its container.
A beaker labeled solid contains a cube of red matter and says has fixed shape and volume. A beaker labeled liquid contains a brownish-red colored liquid. This beaker says takes shape of container, forms horizontal surfaces, has fixed volume. The beaker labeled gas is filled with a light brown gas. This beaker says expands to fill container.
Figure 1. The three most common states or phases of matter are solid, liquid, and gas.
A fourth state of matter, plasma, occurs naturally in the interiors of stars. A plasma is a gaseous state of matter that contains appreciable numbers of electrically charged particles (Figure 2). The presence of these charged particles imparts unique properties to plasmas that justify their classification as a state of matter distinct from gases. In addition to stars, plasmas are found in some other high-temperature environments (both natural and man-made), such as lightning strikes, certain television screens, and specialized analytical instruments used to detect trace amounts of metals.
<span>NaOH + H2O = Na+ and OH- ions.</span>
In order to do conversion on these types of problems. <span>
1.You first have to determine the relationship and the current unit and the target unit which it will be converted into.</span> <span>
2.In this case feet to meters and seconds to minutes</span> <span>
3.Determine the conversion rate: </span>1mi =1609 m<span /> and 1 h = 3600 sec; <span>
4.You first calculate: 1230 m x </span>1 mi/1609 m = 0.764 mi/s
<span>5.<span>Next, is the time which is 0.764 mi/s x 3600s/1hr = </span></span><span>2752.02 mi/h
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Here we have to choose the challenge which is faced by the scientist to make a hydrogen fuel cell by using water.
The challenge that the scientists are facing a. decomposition of water requires a high energy.
For the generation of fuel cells by hydrogen the use of water (H₂O) is a challenging task as the H-O bond in water is so strong and need high activation energy.
As per the mechanism of hydrogen fuel cell generation of H₂ is compulsory. Water remains in its solution as H₂O⇔H⁺ + OH⁻. The breaking of hydroxide ion (OH⁻) to form free hydrogen need a high energy, which cannot meet easily by any energy source.
The sun is always a renewable energy source as the energy of sun is infinitive.
The decomposition of water will only produce oxygen (O₂) and hydrogen (H₂) among which H₂ will be used in the fuel cell and O₂ is not at all harmful.
The excess O₂ is always good for the environment as it is the breathing source in the living system.
