Answer:
Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.
Explanation:
Answer:
In order to safely conduct an experiment, laboratory safety rules must be obeyed.
Explanation:
In order to safely conduct an experiment, laboratory safety rules must be obeyed. The laboratory safety rules are outlined to ensure that the experiment is safe, the safety of people and the environment. The laboratory safety rules are, but not limited to:
1. Dress appropriately for the experiment.
2. Use the necessary personal protective equipment such as gloves and goggles.
3. Do not touch chemicals with bare hands or taste chemicals.
4. Know the specific locations of the fire extinguishers and other safety equipment.
5. Avoid eating and drinking in the laboratory.
6. Dispose laboratory wastes in their appropriate waste bins.
There are other safety rules which depend mostly on the types of experiment, chemicals/materials, and operating conditions for the experiment.
In the 1800s a French scientist named Jacques Charles made discoveries regarding the effect of temperature on gases. Charles law states that at a constant pressure the volume of a given mass of gas is directly proportional to the absolute temperature.
Answer:
1.13 M
Explanation:
Given data
- Mass of luminol (solute): 15.0 g
- Volume of solution = volume of water = 75.0 mL = 0.0750 L
- Molar mass of luminol: 177.16 g/mol
The molarity of the stock solution of luminol is:
M = mass of solute / molar mass of solute × liters of solution
M = 15.0 g / 177.16 g/mol × 0.0750 L
M = 1.13 M
Answer:
See the image 1
Explanation:
If you look carefully at the progress of the SN2 reaction, you will realize something very important about the outcome. The nucleophile, being an electron-rich species, must attack the electrophilic carbon from the back side relative to the location of the leaving group. Approach from the front side simply doesn't work: the leaving group - which is also an electron-rich group - blocks the way. (see image 2)
The result of this backside attack is that the stereochemical configuration at the central carbon inverts as the reaction proceeds. In a sense, the molecule is turned inside out. At the transition state, the electrophilic carbon and the three 'R' substituents all lie on the same plane. (see image 3)
What this means is that SN2 reactions whether enzyme catalyzed or not, are inherently stereoselective: when the substitution takes place at a stereocenter, we can confidently predict the stereochemical configuration of the product.