1. a 2.b 3 a 4. c. 4.a 5. d 6.a. 2Na + Cl2 2NaC 7.c. 3 8.3 9.b
In urea, each nitrogen atom uses three of its valence electrons for formation of single bonds with carbon atom and two hydrogen atoms.
Answer:
density.
Explanation:
A cubic centimeter of water weighs 1 gram. Since a cubic centimeter of vegetable oil weighs less than 1 gram, oil will float on water. Corn syrup is more dense than water so 1 cubic centimeter of corn syrup weighs more than 1 gram. Therefore, corn syrup sinks in water.
The most difficult concept will be the concept of patient drug tolerance because there are many drugs that have different side effects for different patients. Therefore, it is necessary to understand the response of certain drugs to different patients. This will help avoid wrong drug combinations. This can cause side effects.
To learn more about this concept, you need to do your homework on these different drugs and the tolerance reactions you may experience, and attend some drug tolerance seminars, where the speaker will give you more ideas . And a further explanation of the concept.
Another topic in chemistry that is most tough to understand is moles. We can understand this concept by understanding the fact mole is an amount of a substance which may be atoms, molecules, ions, etc which have exactly 6.02214076 * 1023 'elementary entities' of the substance.
To know more about chemistry refer to the following link:
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Answer:
Los elementos de la tabla periódica se distribuyen sobre la base de similitudes.
Explicación:
Los diferentes tipos de elementos se distribuyen en 8 grupos de tabla periódica en función de sus propiedades. Los elementos que tienen propiedades similares se colocan en el mismo grupo. Por ejemplo, el primer grupo de la tabla periódica son los metales alcalinos. Todos los metales alcalinos tienen algunas propiedades similares, es decir, un electrón en su capa más externa, alta reactividad y forma metálica, mientras que, por otro lado, los ocho elementos del grupo son gases nobles que tienen una capa más externa completa y no tienen reactividad.
