Internal hemorrhoids are sometimes painful if they extend outside the anus, or if the blood vessels are clotted (called thrombosed hemorrhoids). 1  First degree: the hemorrhoids remain inside at all times. 2  Second degree: the hemorrhoids extend out of the rectum during a bowel movement but return on their own.
Answers. Best Answer: Rocks can be broken down by physical or chemical weathering. Physical weathering is the cracking, breaking up, and grinding down of rocks into smaller pieces while maintaining the same mineral composition. This type of weathering is caused by a number of different factors. Changing temperatures cause rocks to crack and flake, ice splits rocks open, living things dig or pry open rocks, gravity causes rocks to fall and shatter, and abrasion breaks down rocks with solid particles like sand.
Let's review. Chemical weathering is the process by which rocks are broken down by chemical reactions. There are different types of chemical weathering. Hydrolysis is the chemical breakdown of a substance when combined with water.The most common example of hydrolysis is feldspar in granite rocks changing to clay.his is a very slow process because lichens are slow-growing and the acid they produce is very weak. However, this is a common type of chemical weathering near rivers and streams. So we see that lichens break down rock by producing acid and we see a similar phenomenon with acid rain.