I NEED HELP ASAP! :)

When adding the measurements 42.1014g + 190.5g, the answer has significant figures.
When dividing the measurements 400g/32.2 cm^3, the answer has significant figures.

Which set of characteristics best describes igneous rock? a) largest type of rock, made of organic matter, hardest type of rock b) least abundant type of rock, made of other rocks, made mostly of minerals c) found on all continents, contains wavy bands of stripes, contains fossils d) most abundant type in earth's crust, made of magma/lava, contains no fossils

A2.5% (by mass) solution concentration signifies that there is a 2.5 % (by mass) solution concentration signifies that there is blank of solute in every 100 g of solution. of solute in every 100 g of solution

Citric acid has a ph between 1 and 3.  it is considered to be aa. weak acidb. weak basec. strong based. strong acid