Marni runs 1500 meters around the school track . What does she need to know in order to find out her speed? A) her time from start to finish
B) Her heart rate at the finish line
C) the number of steps she took
D) the time she started.
please hurry, im on a quiz

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

For the reaction, 4 a(g) + 3 b(g) => 2 c(g), the following data were obtained at constant temperature. experiment initial[a],mol/l initial [b],mol/l initial rate,m/min 1 0.200 0.150 5.00 2 0.400 0.150 10.0 3 0.200 0.300 10.0 4 0.400 0.300 20.0 which of the following is the correct rate law for the reaction? 1. rate = k[a]2[b]2 2. rate = k[a][b] 3. rate = k[a]2[b] 4. rate = k[a][b]2

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?