Dmitri mendeleev's periodic law states that chemical and physical properties repeat themselves in groups of?

5. 54 J of heat is required to raise the temperature of a 2.47g unknown substance from 17.10C to 46.70C. a) Calculate the specific heat of the substance b) What is the substance?

How many molecules of sulfur trioxide are in 78.0 grams? (A) 7.33 x 10^23 (B) 5.87 x 10^23 (C) 3.76 x 10^27 (D) 0.974 (E) none of the above

Which electron transition represents a gain of energy? A. from 2nd to 3rd shell B. from 2nd to 1st shell C. from 3rd to 2nd shell D. from 3rd to 1st shell

The gases in air dissolve in water. What would be one way to reduce the amount of a gas dissolved in water? A. add more water B. reduce the air pressure C. increase the air pressure D. stir the water

Be sure to answer all parts. Which is the most likely mode of decay for each of the following? (a) 111 Ag 47alpha decaybeta decayelectron capturepositron decay (a) 41 Cl 17alpha decaybeta decayelectron capturepositron decay (a) 110 Ru 44alpha

If you get pregnant in Dec how long will it take for u to get to second trimester

Name the following compound HClO

Aluminum and Oxygen gas will react to form Aluminum Oxide (Al2O3). When the equation is balanced, How many moles of Al2O3 are formed when a mixture of 0.36 moles Al is ignited? a. 0.12 b. 0.18 c. 0.28 d. 0.46

Which state of the West produces the widest varieties of fruits, vegetables, and nuts? A) California B) Colorado C) Wyoming D) Alaska

A chemical engineer for a fertilizer company is determining the most efficient way to produce ammonia. the engineer carries out the haber reaction under four different conditions.