How many significant figures the measurement have 56.0g 0.0004m 1003ml 0.0350s

In order to do this, we have to first know the significant figure rules.
Rule #1: All non-zero digits are significant. (1234)
 Rule #2: Zeros in front of a number are not significant. (0.093)
 Rule #3: Zeros between non-zero digits are significant. (78309)
 Rule #4: Zeros at the end of a number are significant if there is a decimal point in the number. (0.05470)

So by going by the rules, 56.0g has three sig figs, because there is a decimal point.
0.0004m only has one sig fig, according to Rule #2.
1003ml has 4 sig figs, because the zeroes are wedged in the two sig fig numbers.
And lastly, 0.0350s has 3 sig figs because the number after a decimal point counts.

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.

A.(nh4)(2co3)is the correct answer