<span>A(n) alpha particle is a particle that contains two protons, two neutrons, and has a 2 charge.
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b. alpha
Answer:

Explanation:
P = Pressure = 
V = Volume = 1 cm³
n = Amount of substance
N = Number of atoms
= Avogadro's constant = 
R = Gas constant = 8.314 J/k mol
T = Temperature = 273.15+20 = 293.15 K
From the ideal gas law



The number of atoms is 
Shadows are formed when an opaque object or an object that doesn't allow light to pass through is in the way or infront of etc. a source of light.
Answer:
1.7 m/s²
Explanation:
d = length of the ramp = 13.5 m
v₀ = initial speed of the skateboarder = 0 m/s
v = final speed of the skateboarder = 7.37 m/s
a = acceleration
Using the equation
v² = v₀² + 2 a d
7.37² = 0² + 2 a (13.5)
a = 2.01 m/s²
θ = angle of the incline relative to ground = 29.9
a' = Component of acceleration parallel to the ground
Component of acceleration parallel to the ground is given as
a' = a Cosθ
a' = 2.01 Cos29.9
a' = 1.7 m/s²