To decorate your home, you'll want thick, wide, fancy-looking ribbon. A fabric like velvet adds a nice, classy touch. Ribbon made with wires to help it retain its shape also works well for this bow.

Summary: Choose wide ribbon.


The simplest type of ionic compound is made from exactly 2 elements, 1 metal and 1 non-metal. Their name is always written as 2 element names, plus the -ide suffix attached to the second name.  Examples of simple binary ionic compounds include potassium oxide and sodium phosphide. If the "-ide" suffix doesn't follow a single element name, see instructions for polyatomic ions. For example, "oxide" is a simple oxygen ion, but "hydroxide" and "peroxide" are polyatomic. The first word of the name refers to the metal ion (the positively charged cation). You can find this element on the left side of the periodic table. The second word, ending in -ide, refers to a non-metal ion (the negatively charged anion). Find this on the right side of the periodic table . For example, potassium oxide is a combination of potassium (chemical symbol K, atomic number 19) and oxygen (O, atomic number 8). Notice that the -ide ending is not part of the element name. You're just looking for an element with the same beginning (in this case ox-). In these simple compounds, it is easy to predict the charge of each ion. Each element in a particular column of the periodic table always forms an ion with the same charge:  The Group 1 elements Li, Na, K, Rb, and Cs gain a charge of 1+ (written simply as +). The Group 2 elements Mg, Ca, Sr, and Ba gain a charge of 2+. The Group 13 element Al gains a charge of 3+. The Group 15 elements N and P gain a charge of 3-. The Group 16 elements O and S gain a charge of 2-. The Group 17 elements F, Cl, Br, and I gain a charge of 1- (written as -). It’s crucial to balance the charges in order to write ionic compounds correctly. Electrical forces hold together ionic compounds, pulling the positive and negative ions together. Taken as a whole, the ionic compound is electrically neutral, meaning it has a total charge of zero. (If it had a different charge, it would pull in another atom.) Find the number of atoms of each element that combine to "cancel out" each other's charge and make a neutral compound.  For example, potassium oxide is made up of potassium ions K+{\displaystyle K^{+}} and oxygen ions O2−{\displaystyle O^{2-}}. This means that 2 potassium ions (total charge 2+) balance out the charge of 1 oxygen ion (charge 2-). Here's a shortcut: the first ion's charge (ignoring + or -) tells you the number of atoms of the second ion, and vice versa. For example, aluminum fluoride is made of Al3+{\displaystyle Al^{3+}} and F−{\displaystyle F^{-}} ions. The charge of Al3+{\displaystyle Al^{3+}} is 3, so there are 3 F−{\displaystyle F^{-}} atoms. The charge of F−{\displaystyle F^{-}} is 1, so there is 1 Al3+{\displaystyle Al^{3+}} atom. Write the 2 chemical symbols in the same order they appear in the compound's name (metal then nonmetal). After each chemical symbol, write the number of atoms as subscript (like this{\displaystyle _{like\ this}}). If there is exactly 1 atom of an element, you do not need a number. There is no need to write the charges.  For example, potassium oxide has 2 potassium atoms and 1 oxygen atom. The chemical formula is K2O{\displaystyle K_{2}O}. Aluminum fluoride has 1 aluminum atom and 3 fluorine atoms. The chemical formula is AlF3{\displaystyle AlF_{3}}. Ionic compound formulas are always written in the empirical formula, meaning they’re written with the minimum number of atoms required. If you could balance out the charges with fewer atoms, rewrite the formula. This is the same process as reducing fractions. For example, barium sulfide is made of Ba2+{\displaystyle Ba^{2+}} and S2−{\displaystyle S^{2-}} ions. Using the shortcut above, the barium ion's charge (2) is equal to the number of sulfur ions, and the sulfur ion's charge (2) is equal to the number of barium ions. This gives us the formula Ba2S2{\displaystyle Ba_{2}S_{2}}. However, you don't need this many atoms to balance the charges. Write the 2 numbers as a fraction and simplify: 2 barium atoms2 sulfur atoms=11{\displaystyle {\frac {2\ barium\ atoms}{2\ sulfur\ atoms}}={\frac {1}{1}}}, so the correct formula is BaS{\displaystyle BaS}.

Summary: Identify a binary compound. Look up the 2 elements on a periodic table. Find the charge of each ion. Balance the charges. Write your answer as a chemical formula. Simplify if possible.


Maine Coons are well-known for their friendly, relaxed personalities.  They get on well with children and other pets.  If this sounds like your cat, you might have a Maine Coon. Maine Coons enjoy splashing and spilling water.  They’re even known to splash about in toilets.  If your cat seems to have a special fascination with water, and it shows other signs of being a Maine Coon, it’s possible that it’s a Maine Coon. Most people know that dogs are generally extroverted and faithful.  Maine Coons, likewise, are renowned for their reliable and outgoing behavior.  If your cat greets you in the morning and when you arrive at home, it might be a Maine Coon. Another way to identify a Maine Coon is to get a genetic test.  This involves a vet or other medical professional taking a DNA sample from your cat.  Typically, this is done by swabbing the inside of your cat’s cheek for skin cells, drawing a vial of blood, or clipping a bit of its fur.  The vet will then use this biological sample to compare your cat’s genome against known Maine Coon DNA and look for a match. Genetic tests are about 90% accurate. Maine Coons typically have good health.  However, they are susceptible to two conditions.  One is hypertrophic cardiomyopathy (HCM), a condition that causes the walls of the heart to thicken.  The other condition is feline hip dysplasia, which is caused when Maine Coons’ hips don’t form properly and results in pain and arthritis.  The breeder you obtain your Maine Coon from should screen for HCM before you purchase it. Because Maine Coons are naturally large, there is little you can do to prevent hip dysplasia.  Your vet will help you treat your cat should it develop this condition.
Summary: Look for a friendly demeanor. Check for a love of water. Look for “dog-like” behaviors. Get a genetic test. Monitor the cat’s health.