What is the element name for 2,2​

Name the element in group 17, period 2. (periodic table)

What is the ph of a 0.0010 m hno3? 1.0 3.0 4.0 5.0

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.