Answer:
Carbon atoms in graphite and diamond are arranged in different ways. Hence, the two allotropes of carbon have different physical properties.
Explanation:
Both graphite and diamond are both made of only carbon atoms. However, their physical properties differ from each other. Hence, they are called allotropes. Think about how these carbon atoms are arranged in each of the allotropes.
<h3>Graphite</h3>
In graphite, each carbon atom is bonded to three other carbon atoms. These carbon atoms will be located in the same plane. A chunk of graphite can contain many of these planes.
Each carbon atom has four valence electrons. Three of these electrons will be used in the bonds. The other electron will be delocalized. These electrons would flow between the sheets of carbon atoms. That keeps the sheets separate and allow them to slide on top of each other.
<h3>Diamond</h3>
In diamond, each carbon atom is bonded to four other carbon atoms. These carbon atoms will form a tetrahedral network.
In graphite, there's a significant separation between two adjacent sheets of carbon atoms. The force between the two sheets is rather weak. When a piece of graphite is between two objects that move over one another, the layers in the graphite would also slide over one another. Since the attraction between two adjacent sheets isn't very strong, there wouldn't be much resistance. Hence the graphite acts as a lubricant.
In contrast, most of the carbon atoms in a piece of diamond would be connected to each other. Unlike the sheets in graphite, in a diamond there are almost no moving parts. Also, the forces between neighboring carbon atoms are very strong. When an external force acts on a chunk of diamond, the carbon atoms would barely move. Hence, the structure appears to be very rigid. That gives diamond its abrasive properties.
Answer : The retention time is, 20 min
Explanation :
Retention time : It is defined as the amount of time a compound spends on the column after it has been injected.
Formula of retention time is:
Given:
Distance from injection point to center of peaks = 10 cm
Chart recorded speed = 0.5 cm/min
Now put all the given values in the above formula, we get:
Retention time = 20 min
Thus, the retention time is, 20 min
HELP ME!!!
Project: Modeling potential and kinetic energy
Assignment Summary
For this assignment, you will develop a model that shows a roller coaster cart in four different positions on a track. You will then use this model to discuss the changes in potential and kinetic energy of the cart as it moves along the track.
Background Information
The two most common forms of energy are potential energy and kinetic energy. Potential energy is the stored energy an object has due to its position. Kinetic energy is the energy an object has due to its motion. An object’s kinetic energy changes with its motion, while its potential energy changes with its position, but the total energy stays the same. If potential energy increases, then kinetic energy decreases. If potential energy decreases, then kinetic energy increases.
Potential energy related to the height of an object is called gravitational potential energy. Gravitational potential energy is directly related to an object’s mass, the acceleration due to gravity, and an object’s height.
Materials
One poster board per student Drawing utensils
Assignment Instructions
Step 1: Prepare for the project.
a) Read the entire Student Guide before you begin this project.
b) If anything is unclear, be sure to ask your teacher for assistance before you begin.
c) Gather the materials you will need to complete this project.
Step 2: Create your poster.
a) On the poster board, draw a roller coaster track that starts with one large hill, then is followed by a valley and another, smaller hill.
b) Draw a cart in four positions on the track as outlined below.
i. Draw the first cart at the top of the first hill. Label it A.
ii. Draw the second cart going down the first hill into the valley. Label it B.
iii. Draw the third cart at the bottom of the valley. Assume that the height of the cart in this position is zero. Label it C.
iv. Draw the last cart at the top of the second, smaller hill. Label it D.
c) Make sure that your name is on the poster. Step 3: Type one to two paragraphs that describe the energy of the cart.
a) Type one to two paragraphs describing the changes in potential and kinetic energy of the cart. Be sure to discuss how the potential and kinetic energy of the cart changes at each of the four positions along the track, and explain why these changes occur.
b) Make sure your name is on the document.
c) Later, you will submit this document through the virtual classroom.
Step 4: Evaluate your project using this checklist.
If you can check each criterion below, you are ready to submit your project.
Did you draw a model of a roller coaster track with one large hill, a valley, and a smaller hill?
Did you draw a cart on the track in the four required positions A–D? Did you label the cart at each of the four positions?
Did you type a paragraph describing the changes in potential and kinetic energy of the cart at each of the four positions on the roller coaster track? Did you explain why the changes in potential and kinetic energy occur?
Step 5: Revise and submit your project.
a) If you were unable to check off all of the requirements on the checklist, go back and make sure that your project is complete.
b) When you have completed your project, submit your poster to your teacher for grading. Be sure that your name is on it.
c) Submit the typewritten document through the virtual classroom. Be sure that your name is on it.
Step 6: Clean up your work space.
a) Clean up your work space. Return any reusable materials to your teacher and throw away any trash.
b) Congratulations! You have completed your project.
Electric energy and sink
Answer:
Increasing substrate concentration also increases the rate of reaction to a certain point. Once all of the enzymes have bound, any substrate increase will have no effect on the rate of reaction, as the available enzymes will be saturated and working at their maximum rate.
Answer:
Explanation:
It's because of the sun! Bananas are curved so they can retrieve sunlight.
