Answer:
A population or community research line can be carried out, wherever at a certain point in time, regardless of whether it is a cross-sectional study.
In addition, the people who would be the population to be studied or the object of study might or might not know the cause of the study (blind) while the researcher could be experimentally participatory.
Explanation:
They are prevalence studies, in which the presence of a health condition or state is determined in a well-defined population and in a determined time frame: one day, one week, a particular moment in life, even if it does not temporarily coincide in all the subjects (for example, the blood pressure figures at the time of entering the school or at the beginning of the holidays, the prevalence of diabetes in hospitalized patients on a given day, etc.).
They are like "photographs" of a state of affairs at a given moment. The simultaneous determination of what is understood by exposure and event does not allow defining causality.
Experiments test the scientists' ideas.
Answer:
Avogadro number of representatives particles is equal to one mole.
Explanation:
The number 6.022 × 10²³ is called Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
17 g of ammonia = 1 mole = 6.022 × 10²³ molecules of ammonia
12 g of carbon = 1 mole = 6.022 × 10²³ atoms of carbon
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
Answer:
16.933g approximately 17.0 grams
Explanation:
From the simple promotions and given the same compound ascorbic acid (vitamin C)
In the laboratory synthesised ascorbic acid
Mass of carbon = 30.0g
Mas of Oxygen = 40.0g
That is the mass of Oxygen per unit mass of Carbon
Per gram of Carbon we have
(30.0g Carbon)÷30 combines with (40.0g of Oxygen)÷30
That is 4/3g of Oxygen per gram of Carbon
Hence the mass of Oxygen compound that combines with 12.7g of Carbonin natural occurring ascorbic acid (vitamin C) is = 4/3×12.7 = 16.933g approximately 17.0g