It is known that chlorine is more electronegative than bromine, and thus chlorine is more reactive, and less discriminatory as to what it will react with, thus making bromine more “selective”. Another pertinent piece of information to look at would be stability. The stability of a free radical increases as the number of carbon substituents increases. Therefore, primary is the least stable and tertiary is the most stable. Also, the more stable the free radical that is left behind, the weaker its C-H bond strength will be.
Diffusion is where particles move from where they are in an area of high concentration to where they are in an area of low concentration. Ficks law of diffusion states that: . This shows that the greater the surface area of the diffusion surface the greater the rate of diffusion will be. This is because there is a greater are for the particles to diffuse across if the is a concentration gradient. A good example of where a large surface area is used for a fast rate of diffusion is in the alveoli of the lungs.
Viscosity can be affected by three main factors, Firstly, the higher the temperature, the lower the density of the magma, causing it to flow more easily. Secondly, the greater the amount of dissolved gases in the magma, the less viscous it will be, and lastly the higher the silica content, the more viscous it will be. Thicker, more viscous magma has a greater potential for explosive eruptions and therefore represent the greatest potential hazards. The thickest type of magma is known as Acidic Magma. Its relatively low temperature, high silica content and leads to blockages and powerful eruptions.
After my exercise my temperature was 37.4°C, my pulse rate was 134 beat per minute (bmp), my respiration rate was 35 respiration breath per minute (Rpm) and my blood pressure was 135 over 74 millimetre of mercury (mmHG). There was an increase in my physiological measurements from pre-exercise to post-exercise. My pulse rate increased after exercise because the heart had to beat faster for it to circulate her blood which carried oxygen to the cells. My cells needed enough oxygen supply due to the exercise I did therefore my heart provided the cells with more oxygen which made the pulse rate beat faster. Another reason why my pulse rate increased was because my body was getting rid of waste gases which are CO2 and H2O that are products of respiration.
This extreme pressure change makes the iso bars compact together creating fast moving winds and causing wind speeds to increase to even out the air pressure. 3. Describe the changes in central pressure and sustained wind speed between 29 and 30 August 2005? The air pressure from august 29th to august 30th changed from 904mbars to 985 mbars. While the air pressure increased the winds decrease as iso bars spread apart and wind is no longer moving at an abrupt pace.
What is the reason for this difference in melting points? (3 points) Ionic compounds have higher melting and boiling points than covalent compounds. This is because the electrostatic attraction in an ionic bond is very strong which means lots of heat energy is needed to break it down. Ionic bonds have high melting and boiling points. On the other hand covalent bonds, the intermolecular forces are very weak and is easily broken,hence lesser heat is required and thus covalent bonds have lower melting and boiling points.
Which type of compound usually has higher melting points: ionic compounds or covalent compounds? What is the reason for this difference in melting points? (3 points) - Ionic compounds have higher melting and boiling points than covalent compounds. The electrostatic attraction in an ionic bond is very strong hence a lot of heat energy is required to break it down, ionic bonds have high melting and boiling points. However, in covalent bonds, the intermolecular forces are very weak and easily broken, hence lesser heat is required and thus covalent bonds have lower melting and boiling points.
The metal always had a larger change in temperature than the water, no matter whether the metal started hot or cold. This is because the metal has much less mass than the water in each trial. In general, the part of the system with less mass will change temperature more. 2. Of the four trials, transfer to the first row of this column the data for the trial that came closer to the theoretical value: | | | | | | Best Case | 80.0 g | 285.1 g | -75.1 C° | +1.9 C° | 0.377 |
In the middle course, the river has a smoother bed and banks, making it more efficient. The discharge of the river here is much higher and velocity has increased so the river has much more energy. Having more energy means it can pick up larger particles which erode along the course through abrasion. In the middle course is where waterfalls, meanders and ex-bow lakes occur. Also, as soft rock is being eroded at a faster rate than hard rock, steps in the riverbed are created, causing rapids.
Today’s airbags are much more sophisticated with much faster results. One of the simplest mechanisms that detect rapid frontal deceleration (as experienced during a frontal collision) is a ball that is held in place with a magnet. The ball is dislodged, and moves forward due to inertia when the car decelerates rapidly. The ball then fits in a groove, and completes an electrical circuit that ignites sodium azide. This then causes a chain reaction creating N2 to fill the bag within 40 thousandths of a second.