INPUT ARTICLE: Article: Sometimes, more than one element can combine to form an ion, which can then bond with a different ion to form a compound. For example, OH−1{\displaystyle OH^{-1}} is a polyatomic ion made from oxygen and hydrogen ions. Each polyatomic ion has its own special name. OH−1{\displaystyle OH^{-1}} is called "hydroxide."   OH−1{\displaystyle OH^{-1}} is not an ionic compound, because it does not have a net charge of zero. It is a single ion, which can combine with ions of the opposite charge. Some elements can form polyatomic ions by themselves. For example, "peroxide" is the O22−{\displaystyle O_{2}^{2-}} ion. It contains 2 oxygen atoms, but has a total charge of -2. (This is different than oxide, the "standard" oxygen ion, which has one atom with a charge of -2.) The second word in the ionic compound's name refers to the polyatomic ion. Look up this word (not the full compound name) to find the formula for this polyatomic ion. You can also memorize a few common polyatomic ions:  Cyanide: CN−{\displaystyle CN^{-}} (One carbon, one nitrogen, total charge of -1) Hydroxide: OH−{\displaystyle OH^{-}}. Nitrate: NO3−{\displaystyle NO_{3}^{-}} (One nitrogen, three oxygen, total charge of -1) Nitrite: NO2−{\displaystyle NO_{2}^{-}}  Peroxide: O22−{\displaystyle O_{2}^{2-}}  Sulfate: SO42−{\displaystyle SO_{4}^{2-}}  Sulfite: SO32−{\displaystyle SO_{3}^{2-}} The other ion in the compound is usually a simpler, one-atom ion. You can find its charge the same way you would in any problem. For example, magnesium hydroxide contains a magnesium cation. Magnesium is a group 2 element that forms the ion Mg2+{\displaystyle Mg^{2+}}. All ionic compounds have a total net charge of zero. Find the minimum number of positive and negative ions that balance each other's charges perfectly. Remember that the polyatomic ion is a single ion, and cannot be divided into parts. For example, to balance OH−1{\displaystyle OH^{-1}} and Mg2+{\displaystyle Mg^{2+}} , compare the charges. It takes two -1 charges to balance out one 2+ charge. This means there are two hydroxide ions and one magnesium ion. To show that there are multiple polyatomic ions, enclose that section of the formula in parentheses. Write the subscript showing the number of atoms after the close parenthesis.  In the case that more than one of a certain polyatomic ion is necessary to balance the charge, the entire formula for the polyatomic ion is enclosed in parentheses and the numerical subscript is placed outside the parentheses. This shows that the subscript applies to the entire polyatomic ion.  For example, magnesium hydroxide has the chemical formula Mg(OH)2{\displaystyle Mg(OH)_{2}}. You do not need to include the charges of the ions.

SUMMARY: Understand polyatomic ions. Look up the chemical formula for the polyatomic ion. Find the charge of the other ion. Balance the charges of the 2 ions. Write the formula.


INPUT ARTICLE: Article: Apply moisturizer to your skin at least twice a day focusing on any dry patches of skin. This will help keep it moist and prevent cracking and irritation. Avoid moisturizers with dyes or perfumes that may irritate your skin. Moisturizers and oils should be applied when your skin is still wet after a bath or shower to seal in the moisture. The following work well:  Cetaphil Nutraderm Eucerin Baby oil Allergy medicines contain antihistamines, which may help because eczema is related to allergies. Some good options include:  Cetirizine (Zyrtec) Fexofenadine (Allegra) Diphenhydramine (Benadryl) Some topical creams, such as steroid creams, calamine lotion, and topical calcineurin inhibitors will help to reduce itching. You can apply them to your eczema ta few times per day to get relief. Some options include:  Hydrocortisone cream. A 1% hydrocortisone cream can help to reduce itching. Just keep in mind that frequent use of steroid creams may lead to thinning of the skin, so it is best to use these creams on a short term basis. Ask your doctor before using a hydrocortisone cream on your face or between skin folds. Calamine lotion. Calamine lotion is often used for poison ivy, but it can also help with itching caused by eczema. Topical Calcineurin Inhibitors. These prescription topical creams provide itch and rash relief, but they do not thin the skin like steroid creams are known to do. A cold compress can help to relieve itching and it will also help to reduce swelling. You can either use a cold, wet washcloth or an ice pack as a cold compress.  To use a wet washcloth, hold a washcloth under cool running water and then wring out the excess water. Hold the washcloth on your skin for about five minutes. Then, dry the area thoroughly and apply moisturizer. To use an ice pack wrap it in a clean cotton cloth or paper towel, then hold the ice pack against your eczema for up to 20 minutes. Give your skin a chance to return to its normal temperature before using the ice pack again or you may cause tissue damage. If you scratch, you will irritate the area and may break the skin. This will allow bacteria to get in and make you more prone to infection. If you scratch without thinking about it, try:  Putting a bandage on it. Keeping your nails trimmed. Wearing a pair of cotton gloves at night. This is particularly enjoyable on a cold winter day and it may help to reduce itching and soothe your skin.  Draw a warm bath and then sprinkle baking soda, uncooked oatmeal, or colloidal oatmeal into the water. Relax for 15 minutes, and then get out. Apply moisturizer to your wet skin. This will help seal the moisture into your skin.  Some people wait 20 minutes after drying the skin otherwise the moisturizer can penetrate too quickly causing added irritation. This may sting a bit, but it will help to kill any bacteria that may be growing in the irritated or broken skin. In the summer a swim in the ocean would help, but during winter, you will need to mix your own salt solution.  Dissolve several teaspoons of table salt into a cup of warm water. Using washcloth, dab it onto the eczema patch and let it dry. Always consult your doctor before trying alternative medicines, particularly herbal supplements, which may interact with other medications. These methods have not been scientifically proven to help, but anecdotal evidence suggests they may help some people:  Supplements of vitamin D, E, zinc, selenium, probiotics, or various oils Herbal supplements like St. John’s wort, calendula flowers, tea tree oil, German chamomile, Oregon grape root, licorice, rice bran broth (topically) Acupuncture or acupressure Using aromatherapy or color therapy to increase relaxation Massage therapy During the winter, the days are shorter and we spend more time indoors, reducing the amount of light we are exposed to throughout the day. Light therapy can be done by deliberately exposing yourself to sunlight, or using artificial ultraviolet A, or narrow band UVB light. However, this can be harmful and is generally not used on children. Side effects include:  Early aging of the skin A risk of developing skin cancer

SUMMARY:
Use moisturizer to soothe dry winter skin. Try an over-the-counter allergy medication. Treat the itching with a topical cream. Soothe itchy, inflamed patches with a cold compress. Prevent yourself from scratching. Take a baking soda or oatmeal bath. Dab saltwater onto the eczema. Experiment with alternative medicines. Try light therapy to reduce inflammation.