Answer:
C2H5OH has a greater boiling point.
Explanation:
It is a bigger molecule than C2H6.
"I" symbol means the current goes through the system (imagine the 'I' being a line, like a circuit connecting [power to the device]) "O" symbol means the current does not go through the system. ( the circle is an open circuit, having no power flowing through it
In a food chain we arrange the energy in the form of a pyramid.
The producers are on the base of pyramid and then consumers are towards peak.
in the given food chain grass is being eaten by grasshopper which are food of birds.
Grasshoppers are also eaten up by Hawks. so both brids and hawks are feeding upon grasshoppers thus the amount of energy transferred from the grass to the grasshopper is the same as the amount of energy transferred from the grasshopper to the bird.
Answer:
Explanation:
When we are given Bohr models, we will be given a circle with rings surrounding it. The circle in the center of the model represents the nucleus, which contains the neutrons and the protons. The rings will have spherical structures that are attached to them in an orderly fashion - these model the electrons of an atom.
- Protons are positively-charged subatomic particles that also identify the atom's chemical identity and atomic number. Using the number of protons, we are able to identify the element.
- The neutrons are the neutrally-charged subatomic particles that give an atom its weight. When you look at a traditional periodic table, you'll see that the square that houses an element has its symbol, atomic number, and atomic mass. The atomic mass is equivalent to the sum of the protons and neutrons.
- Electrons are negatively-charged subatomic particles that give an atom its overall charge. In order for an atom to be stable and neutral, the electrons <u>must</u> equal the protons. Otherwise, we have an unstable atom called an ion with either a positive or a negative charge. This is dependent on whether an atom has gained or lost electrons.
When we reference the model, we will see that there are 13 "p" and 14 "n" within the green circle. The "n" refers to <em>neutrons </em>and the "p" refers to <em>protons</em>. We can also count the red spheres and make quick observations about these: there are 2 red spheres on the innermost ring - for simplicity reasons, we will title this ring as r = 1. There are 8 red spheres on the middle ring - this ring will be titled r = 2. Finally, we can see that there are 2 more electrons in the outermost ring - this ring will be titled r = 3.
Now, because we have 13 protons, we know that the protons are equivalent to the atomic number.
- If we check the periodic table, we will see that Silicon (Si) has an atomic number of 14. This doesn't match the number of protons, so we can rule out that a silicon atom is not the element shown.
- When we use the same process and check aluminum, we discover that Aluminum (Al) has an atomic number of 13. Since the number of protons and the atomic number are equal, we can conclude that this is the element.
- If we check Helium (He), we see that it has an atomic number of 2, so this is definitely not our element in question.
Now that we have concluded that Aluminum is our element, we can check this to be sure. If we use the formula m = n + p (where m is the atomic mass, n is the neutrons, and p is the protons), we can check to be sure we have selected the right element.
The given mass of aluminum on the periodic table is 26.982 atomic mass units. We round to the nearest integer when it comes to this, so we round 26.982 up to 27 even.
Now that we have determined the atomic mass and we are given the number of both protons and neutrons, we can act as if we weren't given the amount of neutrons and only the mass and amount of protons. We can then use the equation to solve for the amount of neutrons and check that the selection we made is correct.
<u>Steps</u>
- Substitute 27 for <em>m</em> and 13 for <em>p</em>.
- Subtract 13 from both sides to isolate the <em>n</em> and place the constants on the same side of the equation.
- Combine like terms by taking the appropriate operations (in this case, this is subtracting 13 from 27).
- Finally, because we are solving for <em>n</em>, you can reverse the equation (place the constant on the right and place the variable on the left; i.e., 72 = x → x = 72).
The work we just performed will allow us to confirm that because we solved for <u>14 neutrons</u>, Aluminum (Al) is indeed the element represented by the model.
Hope this helps! :)
The starting material or materials for a chemical reaction are referred to as the reactants. The substance or substances produced from a chemical reaction are called products. Sometimes a secondary product, a byproduct, can also be created at the same time as the desired product(s).
Not every chemical reaction occurs in the same way. There are different types of chemical reactions, including synthesis reactions, decomposition reactions, and displacement reactions. In this experiment, a decomposition reaction takes place. During a decomposition reaction, a compound breaks apart into two or more products. Most decomposition reactions need an outside source of energy in order to take place.
Hydrogen peroxide is not a very stable compound, so it slowly decomposes into water and oxygen gas under normal conditions. In this reaction, yeast is used as a catalyst. A catalyst is a substance that helps to change the rate of a reaction. During the reaction, the catalyst is not consumed. As a result, the yeast makes the reaction occur much faster; it causes the hydrogen peroxide to break down and release the oxygen gas much faster.
The soap is used to help us “see” the reaction. Bubbles of oxygen become trapped in the soap, creating foam. The reaction occurs so quickly, releasing so much gas and creating so much foam, that the foam begins to flow out of the bottle. The result of this reaction looks like toothpaste being squeezed out of a tube.
In addition, the bottle will feel warm to the touch because the reaction is exothermic. An exothermic reaction or process is one that gives off energy. In contrast, an endothermic reaction or process is one that requires or absorbs energy.
HYPOTHESIS
uAdding yeast to hydrogen peroxide
will cause the hydrogen peroxide to
decompose quickly into water and oxygen gas, creating foam as the gas becomes trapped in liquid dish soap and pushes upward out of the bottle.
FORMULAS & EQUATIONS
Hydrogen peroxide is a relatively clear liquid substance. It is soluble in water and is often sold as a mixture of H2O2 in water. The hydrogen peroxide used in this experiment is actually a 6% solution of H2O2 in water.
The chemical formula for hydrogen peroxide is H2O2.
Hydrogen peroxide naturally decomposes into water and oxygen gas. The reaction is shown by the following equation:
2H2O2 (aq)g2H2O (l) + O2 (g)
The rate of the reaction can be increased by introducing a catalyst. In this experiment, the catalyst is yeast. Yeast is a microorganism that is part of the fungi family. Therefore, in the equation below, the catalyst is indicated above the arrow.
yeast
2H2O2 (aq) g 2H2O (l) + O2 (g)
The hydrogen peroxide used in the experiment is
actually a mixture of water and hydrogen peroxide.
CONNECT TO THE YOU BE THE CHEMIST CHALLENGE
For additional background information, please review CEF’s Challenge study materials online at http://www.chemed.org/ybtc/challenge/study.aspx.
• Additional information on elements, compounds, and physical and chemical changes can be found in the Classification of Matter section of CEF’s Passport to Science Exploration: The Core of Chemistry.
• Additional information on chemical reactions can be found in the Chemical Reactions section of CEF’s Passport to Science Exploration: Chemistry
