The radius of a spherical aluminum atom is 140 picometers. How many aluminum atoms could be lined up across a length of 27.9 cm.

9.96 × 10⁸

Explanation:

Step 1: Calculate the diameter of 1 aluminum atom

The diameter of a sphere is 2 times the radius.

d = 2 × 140 pm = 280 pm

Step 2: Convert "d" to m

We will use the conversion factor 1 m = 10¹² pm.

280 pm × 1 m/10¹² pm = 2.80 × 10⁻¹⁰ m

Step 3: Convert the total length (L) to m

We will use the conversion factor 1 m = 100 cm.

27.9 cm × 1 m/100 cm = 0.279 m

Step 4: Calculate the number of atoms of aluminum required

We will use the following expression.

L/d = 0.279 m/2.80 × 10⁻¹⁰ m = 9.96 × 10⁸

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.