What is the measurement 1042 l rounded off to two signicant digits ?

After watching the video "zinc strip in copper nitrate solution", and reading the instructions, click on the link labeled "start" just below the drawing of the pencil tip. follow the direction to complete the 3x3 grid. answer the below questions for the portion of the activity in which sn(s) is placed in agno3(aq)

An observation that requires measurement is called quantitative observable or qualitative

What is the atomic number of an atom that has 6 protons