The pile of ash left after a fire burns out demonstrates what concept? A. Original materials remain after a physical change. B. A chemical change forms new substances. C. Physical properties are never stable. D. Fire recycles most substances.

37 Which general trends in first ionization energy and electronegativity values are demonstrated by Group 15 elements as they are considered in order from top to bottom? (1) The first ionization energy decreases and the electronegativity decreases.

True or false the sun is a renewable resource

Which type of condensation nuclei are most likely to cause clouds to form? a. smoke particles b. dust particles c. salt particles?

Antony was measuring the temperature of a solution when he accidentally dropped the thermometer on the floor. What should Antony immediately do next?

What molecule contains 12.17 g of carbon, 32.53 g of sulfur, and 72.19 g of chlorine

What is the difference between potassium 39, 41, and 40

What is physical chemistry?

Which of the following happens during a solar eclipse? The moon appears red. The moon casts a shadow on Earth. Earth, the moon, and the sun form a triangle. Earth comes between the sun and the moon.

The four elements comprising over 90 of living matter are

Consider the gas-phase reaction, n2 (g) + 3 h2 (g) 2 nh3 (g), for which kp = 43 at 400 k. if the mixture is analyzed and found to contain 2.0 bar of n2, 2.0 bar of h2 and 27.0 bar of nh3, describe the situation: