64. Classify each change as physical or chemical. Even if you are incorrect in your assessment, you should be able to defend why you chose as you did. (a) Grape juice turns to wine. (b)...
Richard from Cleveland, OH's Resources
. What is the electric charge on the calcium ion in calcium chloride, CaCl2?
Barium ions carry a 2+ charge, and nitrogen ions carry a 3- charge. What is the chemical formula for the ionic compound barium nitride
2. How many oxygen atoms are indicated on the right side of this balanced chemical equation? 4 Cr(s) + 3 O2( g)h2 Cr2O3( g)
46. Balance these equations: (a) ____Fe(s) + ____O2(g)h____ Fe2O3(s) (b) ____H2(g) + ____N2(g)h____NH3(g) (c) ____Cl2(g) + ____KBr(aq)h____Br2(l ) + ____KCl (aq) (d)...
What is the approximate mass of a carbon atom in atomic mass units? How about a carbon dioxide molecule
. Which contributes more to an atom’s mass: electrons or protons? Which contributes more to an atom’s size?
. Which has more atoms: a 1-g sample of carbon-12 or a 1-g sample of carbon-13? Explain
If two protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains?
. The atoms that make up your body are mostly empty space, and structures such as the chair you’re sitting on are composed of atoms that are also mostly empty space. So why don’t you fall...
Imagine that you want to create an activity for a group of children to simulate the periodic table. Suggest items that you may use and how they may be organized in rows and columns. Be creative. Share...
86What happens to the brightness of light emitted by a lightbulb when the current in the filament increases
72Why do clothes often cling together after tumbling in a clothes dryer
. Why is charge usually transferred by electrons rather than by protons
40Calculate the power of a hair dryer that operates on 120 V and draws a current of 10 A.
38Calculate the current in the 240-_ filament of a bulb connected to a 120-V line. Power _ IV
58. Which has the higher specific heat capacity: an object that cools quickly or an object of the same mass that cools more slowly?
. The photo shows physics teacher Marshall Ellenstein walking barefoot on broken glass bottles in his class. What physics concept is Marshall demonstrating, and why is...
Two identical balloons of the same volume are pumped up with air to more than atmospheric pressure and suspended on the ends of a stick that is horizontally balanced. One of the...
. Show that the water pressure at the bottom of the 50-m-high water tower in Figure 5.3 is 490,000 N/m2, or is approximately 500 kPa