What is questions #2-b and questions # 3?

give a particulate-level explanation of why ice (solid water) is less dense than liquid water?

Question 20 Which of the following correctly describes an energy transformation that can be observed in an everyday situation? A Gasoline burns and powers a car engine when the bonds are broken between the molecules and the free electrons flow. This is a transformation between electromagnetic energy and chemical energy.   B Ice in soda glass melts when it is placed in sunlight on a window sill. Radiant energy from the sun is absorbed by the water molecules, which increases the speed that the molecules move. This is a transformation between light energy and kinetic energy.   C A pot of water is heated by a stove as the heat energy moves from the stove top to the metal of the pot. This is a transformation between mechanical energy and thermal energy.   D The sun is powered by the fusion of large atomic nuclei that creates heat and light for the solar system. This is a transformation between chemical energy and light energy.

Which of the following is a pure substance that can be broken down into simpler substances by chemical means? Solution Compound Heterogeneous mixture

Gasoline is composed of a variety of different liquid hydrocarbons, which do not separate as time passes. Gasoline is an example of a: A) heterogeneous mixture B) Chemical compound C) Chemical element D) Solution

= 24 = 25 = 26 27 = 28 29 = 30 F 31 = 32 = 33 34 35 36 Calculate the amount of heat needed to boil 14.8 g of ethanol (CH,CH,OH), beginning from a temperature of -26.4 °C. Round your answer to 3 significant digits. Also, be sure your answer contains a unit symbol. dh Submit Assignment Continue MacBook Air A. FI F12 F9 F10 FIC FB 000 D00 F4 F7 20 F6 F5 esc F3 F1 & deleto $ %D @ 7 8 2 3 4 5

Use the image to answer the following question. ННННН НННН ННННН H-C-C-C-C-Ç-C-C-C-C-Ç-C-C-C-C-C HH HHHHHHHHHHHH OH An engineer is developing a new material that would allow electricity to flow. Which of the following materials would an engineer choose and why? O A. Copper, because it contains ions that have the ability to conduct electricity. O B. Carbon, because it is a good insulator. O C. Copper, because it is a good insulator. D. Carbon, because it contains ions that have the ability to conduct electricity.

Part A- Does a liquid release energy or absorbs energy when it changes to a solid?(think of when water changes to ice).     A-release energy B-absorbs energy Part B- Absolute zero is the freezing point of water- 0 degrees Celsius and 0 degrees farenheight A-True B-False

Every year Every second (1 year 365 days).

Consider the two spheres shown here, one made of silver and the other of aluminum. The spheres are dropped from a height of 1.7 m. Composition - aluminum Density= 2.70 g/cm³ Volume 196 cm³ Composition - silver Density 10.49 g/cm³ Volume=196 cm³ What is the kinetic energy of the silver sphere at the moment it hits the ground? (Assume that energy is conserved during the fall and that 100%% of the sphere's initial potential energy is converted to kinetic energy the time impact occurs.) Express your answer to two significant figures and include the appropriate units. Ek = Value Units