Answer:
Explanation: Covalent bonding occurs when pairs of electrons are shared by atoms. Atoms will covalently bond with other atoms in order to gain more stability, which is gained by forming a full electron shell. By sharing their outermost (valence) electrons, atoms can fill up their outer electron shell and gain stability.
Answer:
detecting and indicating an electric current
Answer:
9.34 N
Explanation:
First of all, we can calculate the speed of the wave in the string. This is given by the wave equation:

where
f is the frequency of the wave
is the wavelength
For the waves in this string we have:
, since it completes 625 cycles per second
is the wavelength
So the speed of the wave is

The speed of the waves in a string is related to the tension in the string by
(1)
where
T is the tension in the string
is the linear density
In this problem:
is the mass of the string
L = 0.75 m is the its length
Solving the equation (1) for T, we find the tension:

Axial Tilt and Sun Energy
This axial tilt means that during the Earth's journey around the sun the poles receive varying amounts of sunlight. The equator, however, receives relatively consistent sunlight all year. The consistency of energy means the equator's temperature stays relatively constant all year.
Answer:
$900 trillion
Explanation:
If Alaska is 20% of the contiguous US, then the approximate area of interest is ...
1200 miles × 3000 miles = 3.6×10^6 square miles.
The size of a dollar bill is about ...
(6.5 cm)·(15.5 cm) = 100.75 cm^2
One mile is 160,934.4 cm, so 1 square mile is about ...
1 mi^2 = (160,934.4 cm)^2 ≈ 2.59·10^10 cm^2
The number of dollars of interest is then ...
(3.6 · 10^6 mi^2)(2.59 · 10^10 cm^2)/(100.75 cm^2) ≈ 9.3·10^14
≈ 930 × 10^12 . . . dollars
It would cost about 900 trillion dollars to cover the land area of the US in $1 bills.