After reading about the kinds of changes that occur, Yara saw some rust on a pipe that was going into her house. What kind of change is the formation of rust? *

reactant
product
chemical
physical​

chemical

Explanation:

Chemical change is a type of change that involves the formation of new substances. The process of forming this new substance is irreversible i.e. cannot be changed back into it's normal form. Chemical changes is characterised by color changes, gas evolution etc.

In this case, a RUST on a pipe is being described. This rust is a type of chemical change because it involves a change in color and also a new substance is formed.

answer; ///i do believe that the correct answer is (b); ///particle composed of two or more atoms bonded together;

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).