Answer:
15.3 %
Explanation:
Step 1: Given data
- Mass of the sample (ms): 230 g
- Mass of carbon (mC); 136.6 g
- Mass of hydrogen (mH): 26.4 g
- Mass of nitrogen (mN): 31.8 g
Step 2: Calculate the mass of oxygen (mO)
The mass of the sample is equal to the sum of the masses of all the elements.
ms = mC + mH + mN + mO
mO = ms - mC - mH - mN
mO = 230 g - 136.6 g - 26.4 g - 31.8 g
mO = 35.2 g
Step 3: Calculate the mass percent of oxygen
%O = (mO / ms) × 100% = (35.2 g / 230 g) × 100% = 15.3 %
Greater amplitude waves have more energy and greater intensity, so they sound louder. ... The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source.
X-Ray used to Take images of teeth and bones.
Ultraviolet night vision goggle
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.
