Round off each of the following numbers to two significant figures:

(a) 0.436

(b) 9.000

(c) 27.2

(d) 135

(e) 1.497 X 10-3

(f) 0.445

Match the substance with its chemical formula. 1. hydroxide ion 2. hydronium ion 3. hydrogen ion H + H 3 O + OH -

Which of the following is a valid mole ratio from the balanced equation 2C3H6 + 9O2 → 6CO2 + 6H2O? 1 mole of C3 H6 / 2 moles of C O2 6 moles of H2 O / 9 moles of O2 2moles of C3 H6 / 6 moles of O2 3 moles of H2 O / 2 moles of C O2

An isotope of mercury has 80 protons and 120 neutrons. whatis the mass number

1. What is the mass of 25.0 L of neon at STP?

Which group is in the leftmost column on the periodic table?

What is potential energy? The energy of change The energy of position or composition The energy of mass or volume The energy of motion

How many significant figures are in the measurement 0.023040 cm?

Can y'all give me some examples of physical changes

A nitrogen-containing compound shows no absorption band at ∼3400cm-1 and no absorption bands between ∼1700cm-1 and ∼1600cm-1. what class of compound is it

What is the mass of 35.2 ml of a solution that has a density of 1.12 g/cm (in dimensional analysis)