Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.
The mole<span> is the </span>unit of measurement<span> in the </span>International System of Units<span> (SI) for </span>amount of substance<span>. It is defined as the </span>amount<span> of a </span>chemical substance<span> that contains as many representative particles, e.g., </span>atoms<span>, </span>molecules<span>, </span>ions<span>, </span>electrons<span>, or </span>photons<span>, as there are atoms in 12 </span>grams<span> of </span>carbon-12<span> (</span>12<span>C), the </span>isotope<span> of </span>carbon<span> with </span>relative atomic mass<span> 12 by definition.
so to solve the moles, divide the mass with molar mass
moles = 4177 g / </span><span>133.34 g/mol
moles = 31.33 moles</span>
Answer:
D. Sweat evaporates from your skin
Explanation:
A physical change is a reversible process, no new substance is formed. A physical change does not affect the chemical composition of a substance.
Sweat evaporation from the skin is a physical change, because the change that occur is merely a change of state, Liquid to Gaseous state, no new substance is formed.
Adding and subtracting with scientific notation may require more care, because the rule for adding and subtracting exponential expressions is that the expressions must havelike terms<span>. Remember that to be </span>like terms<span>, two expressions must have exactly the same base numbers to exactly the same powers. Thinking about decimal arithmetic, the requirement that we have the same powers makes sense, because that guarantees that all of the place values are lined up properly.</span>
A cell is like a factory in many ways.
For one, the cell typically contains many organelles that have several varying functions. In a factory, you have many workers who perform different tasks, just as the organelles in the cell do.
Another reason is that cells contain a nucleus or the boss/brain of the cell. In factories, this could be considered the boss of the workplace that tells each and every worker, or organelle, what to do.
The selectively permeable membrane of a cell also resembles a factory as it only lets in workers or special guests. The cell's membrane only lets in specific materials, hence the selectively permeable membrane.
These are just a few ways as to how the cell is like a factory.
Hope this helps!
