First, list each element present in the molecule. You may use the chemical symbol or write out the name of the element. Then, count the atoms according to the molecular formula and write them next to the element's name or symbol. For example, carbon dioxide or CO2, list that there is 1 carbon (C) and 2 oxygens (O) present in the molecule. For methane, CH4, list carbon (C) and hydrogen (H). Methane comprises 1 atom of carbon and 4 atoms of hydrogen. For glucose, C6H12O6, list carbon (C), hydrogen (H), and oxygen (O). Glucose comprises 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen. Use a copy of the Periodic Table of Elements. The Periodic Table lists the atomic mass of each element below the chemical symbol. For example, oxygen has a relative atomic mass of 15.9994 amu. For carbon dioxide (CO2), the relative atomic mass is 12.011 amu for carbon and 15.999 for oxygen. The atomic mass of an element is roughly equal to the summed mass of the protons and neutrons that it contains. Note that the relative atomic mass you find in the periodic table is scaled: it accounts for all of the isotopes of the element in the proportions that they naturally occur. Multiply the atomic mass of each element by the number of atoms of that element: (Atomic Mass of Element) x (# of atoms of that element). Do this for each element in the molecule. In our carbon dioxide example, the mass of the single carbon atom is 12.011 amu. Since there are 2 oxygen atoms, you would write 15.9992=31.998amu{\displaystyle 15.999*2=31.998amu}. Molecular weight = ((Atomic Mass of Element)n x (# of atoms of that element)n) Round the answer as necessary, using significant digits. Remember to use the proper units. amu is the old abbreviation for atomic mass units, but the "most correct" modern unit is a lower-case u. For carbon dioxide, the molecular weight can be found like so: 12.011+31.998=44.009u{\displaystyle 12.011+31.998=44.009u}.

Summary: Count how many atoms of each element exist in the molecule. Find the relative atomic mass of each element in the molecule. Calculate the total mass for each element in the molecule. Add up the mass of all the atoms to find the molecular weight.

Figure out what you would like to be paid for writing. You may have different rates for different outlets; for example, you might charge less to write an article for a nonprofit organization's blog than you would for a larger business. You can be flexible on your rates, but you should establish a standard. It's important to have rates so that you have a fee to quote if you are hired for a writing job. There are many websites and other publications that need writing, but they often don't know what to charge. Give them a starting point and negotiate depending on length, difficulty and time involvement. It's also important to not charge too little. If you are constantly undercutting your rates, you may find it difficult to raise them and earn what you really deserve. If you are trying to get writing jobs that pay by the piece, you may get many small payments. It can be easier for many employers or outlets to pay you through a simple payment service like PayPal. You can usually register for free on an online payment service like PayPal, but they may take a small percentage of your pay. If you're making money, you'll likely have to claim it on your taxes. Make sure you keep meticulous records of your income, including job, date, and amount. If you are collecting royalties from a book, remember that this is also taxable income. Show your clients that you are an active writer who is currently working. Even if you're not getting paid, you should still have relevant, current examples of your writing available on your website. Every six months or so, comb through your writing to find the best of your recent work. Add one or two of these to your portfolio.
Summary: Establish your rates. Get an online payment account. Keep track of your writing income. Keep your materials up-to-date.