Which of these is a demonstration of a chemical change? A. ice melting into water B. wood becomes charred and black from burning C. water evaporates from a sugar solution, leaving behind sugar crystals D. a balloon suddenly popping

Magnesium and iron are metallic elements. How does a mole of magnesium compare with a mole of iron? a) A mole of iron has more atoms. b) They both have the same mass. c) A mole of magnesium has more mass. d) They both have the same number of atoms.

What molecules have tetrahedral arrangement of electron pairs but is not a tetrahedral molecule. Methane Water Carbon dioxide Boron trifluoride

If The mass of a box is increased and the force stay the same, determine the relationship with acceleration

Phosphorus-32 ahs a half-life of 14.0 days. Starting with 8.00 g of 32 P, how many grams will remain after 56.0 days

If 507 g FeCl2 were used up in the reaction FeCl2 + 2NaOH Fe (OH) 2 (s) + 2NaCl, how many grams of NaCl would be made? A. 467.52 g NaCl B. 1014 g NaCl C. 233.76 g NaCl D. 649.05 g NaCl,

It is snowing where Jenna lives. It's been snowing all day, but now the snow has changed to sleet and then to freezing rain. What is happening to cause these changes?

Liquid sample a has a higher vapor pressure than liquid sample b (both in closed containers). what can be said about sample a compared with sample b?

A neutral atom has high electronegativity. Describe what happens to this atom during ionic bond formation?

Which daughter element is produced from the beta decay of 89/36 kr

What is "change" when we are talking about natural and physical systems? A. Information that has been proven to be true B. Repeated processes that are used in a variety of ways C. A process for using knowledge and skills to acquire new knowledge D.