the mass number minus the atomic number
Answer: B. Allegheny plateau
Explanation: Allegheny plateau is a mountainous region that makes up the northern part of the United States of America, the following states are located on the Allegheny plateau New York, Pennsylvania, West Virginia and Ohio, it is made up of HORIZONTAL SEDIMENTARY BEDROCK at elevated lands. Allegheny plateau is over 40million area is over 40million acres,it has been a site for Erosion and for millions years,through this erosions some areas have been brought low while others are higher following the deposition of materials by the erosion.
Physical change 1 is the answer
B
Assume north and east as two sides of a right angled triangle. magnitude of the distance is then given by the length of the hypotenuse which is 
where a = 1.2 km north
and b = 1.6 km east
magnitude = 2 km
Direction is given by the angle between them, that is atan(a/b) = 36.86 deg north of east = 53.1 deg east of north.
Answer:

Explanation:
The energy of a photon is given by:

where
h is the Planck constant
c is the speed of light
is the wavelength of the photon
In this problem, we have a microwave photon with wavelength

Substituting into the equation, we find its energy:
