A gas cylinder contains exactly 15 moles of oxygen gas (O2). How many molecules of oxygen are in the cylinder

Explanation:

The answer is 9.03 × 10²⁴ molecules.

Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance.

Make the proportion.

6.02 × 10²³ molecules per 1 mol

x per 15 mol

6.02 × 10²³ molecules : 1 mol = x : 15 mol

x = 6.02 × 10²³ molecules * 15 mol * 1 mol

x = 90.3 × 10²³ molecules

x = 9.03 × 10 × 10²³ molecules

x = 9.03 × 10²³⁺¹ molecules

x = 9.03 × 10²⁴ molecules

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

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