Answer:
answer is B new substances are formed but their properties are the same as the original substances.
Explanation:
Photosynthesis is the process through which plants convert light energy into chemical energy.
1. The reaction for this would be:
Sn + 4 HNO₃ → SnO₂ + 4 NO₂ + 2 H₂O
The first observation would be bubbling of the solution and brown acrid smoke is produced due to the presence of NO₂ gas. Another observation would be the presence of a white solid which is SnO₂.
2. Heating was required to get rid of the H₂O. When all moisture is gone, you weigh the sample. Afterwhich, you further heat it to get ride of the oxygen. By doing this, you would know the individual mass of each element. Then, you can solve for the empirical formula of the oxide of tin.
Q1. The answer is b) studying chemicals containing carbon.
Pure chemistry, as its name suggests, is the study of pure, basic theory of chemistry, and has no applied aspect. On the other hand, there is applied chemistry with research for some intended purpose and application. Now let's take a look at the choices: effects of drugs on human (purpose is understanding drug effects), a cure for osteoporosis (applied aspect), an antidote for a new strain of virus (applied aspect) are examples of applied chemistry because they have some purpose. On the other hand, studying chemicals containing carbon has no applied aspect, it is a study because of pure knowledge.
Q2. The answer is d) structure of a muscle cell.
Among choices, only the structure of a muscle cell is not visible to human eyes. Imagine foam insulation, X-ray of a knee joint, a shape of a plant - all of these are visible to human eyes. However, if you want to see a structure of a muscle cell, you will need a microscope. The microscopes are able to magnify specimens and are used to see structures that you cannot see with naked eye.
Q3. The answer is d) responding.
An independent (manipulated) variable is variable that is not affected during the experiment. It is what experimenter controls. A responding variable is also called a dependent variable. The dependent (responding) variable is called dependent because it depends (it responds) on the independent variables. It is what is affected and what is observed during the experiment.
Answer:
hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas
Explanation:
Hydrogen is part of the Noble gas family
Answer:
I believe it is hydrogen for the first and methane for the second.
Explanation:
Answer to 8: The most dangerous or harmful gas to humans in the atmosphere would be carbon dioxide. But reserchers have found that methane levels in ancient air samples and found that scientists have been vastly underestimating the amount of methane humans are emitting into the atmosphere via fossil fuels.
Answer to 7: The type of gases present are as critical to density as elevation and gravity, and all are interrelated. Certain atmospheric gases will create thick atmospheres. For example, atmospheres with abundant hydrogen tend to be thicker as gases will combine with hydrogen for greater mass.
Hope this helps!