The most common allotropes are:-
White phosphorus
Red phosphorus
The red one is an intermediate phase between white and violent phosphorus.
When mixing substances, in order to find the final temperature after mixing, it is important to remember that the energy released should be equal to the energy absorbed by the system. We calculate as follows:
Q1 = Q2
(mCΔT)1 = (mCΔT)2
100 ( 90 - T ) = 50 ( T - 10 )
T = 63.33 °C
Explanation:
The half-life is the time taken for a radioactive substance to decay to half of its original composition.
Let us assume that the original amount is x atoms;
Half - life = 60days
Days Composition Half-life number
0 x 0
60 x/2 1
120 x/4 2
180 x/8 3
240 x/16 4
300 x/32 5
360 x/64 6
The fraction that would be left after 360 days will be ![\frac{1}{64}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B64%7D)
Answer:
benzamide
Explanation:
Compound melting Point ,ºC Melting Pont Mixture, ºC
X 131 - 133
trans-cinnamic 133 - 134 110 - 120
acid
benzamide 128 - 130 130-132
malic acid 131 -133 114 -124
Benzoin 135 - 137 108 - 116
The compound X is benzamide since the melting point range is the one closest to this compound ( 130-132 ºC)
The reason there is not an exact match is not due due to the presence of impurities. The presence of impurities always lower the melting point ( it is a coligative property such as the melting point depresion of salt and water )
The reason for the deviation must be be some other factors such as preparation of the sample in the capillary, errors in reading the thermometer, rate of heating, etc.
Q: Which type of severe weather is related to high-pressure systems
A: A high pressure system is a whirling mass of cool, dry air that generally brings fair weather and light winds. When viewed from above, winds spiral out of a high-pressure center in a clockwise rotation in the Northern Hemisphere. These bring sunny skies. A high pressure system is represented as a big, blue H.
If you take this answer into consideration knowing the weathers, you will get your answer