The half-life of radium-226 is 6400 years. If I have 6750 g after 25,000 years, how much radium-226 did I have in my original sample when I started? I had___g in my original sample. Record your answer to the nearest whole number

Which of the halide ions (f-, cl-, br-, and i-) is the most stable base? which is the least stable base?

What volume would 2.25 moles of Ne gas occupy at STP?

Charge on monatomic ions: a) I b) Sr c) K d) N e) S f) In

Precision is ___ a) the degree of exactness in a measurement. b) the degree to which a measurement approaches a standard value. c) the degree to which a measurement misses a standard value. d) the degree of accuracy in a measurement.

What are the concentrations of hydrogen ion and hydroxide ion in household ammonia, an aqueous solution of nh3 that has a ph of 11.50?

How many moles are in 10 grams of CaCl2?

Which is the correct formula for phosphorus pentachloride? PCl4 because a subscript of 4 indicates four Cl atoms PCl5 because a subscript of 5 indicates five Cl atoms P5Cl because a subscript of 5 indicates five P atoms P5Cl3 because a subscript of

Why are the elements in groups 3 to 12 often used to make dyes?

What is not needed for corrosion of metals? a. oxygen c. water b. ions d. sunlight

What force can move the oceans