The copper and oxygen and oxygen atoms are not ions, and the bonds are more covalent than they are ionic.
Answer: Because new theories can come out that better explain observations and experimental results can replace old theories.
Explanation: Theories more than ten years old are usually out of date. Scientists want to prove that the work of other scientists is wrong. New evidence that supports a change prompts scientists to modify earlier theories.
Answer:
3.2m
Explanation:
Given parameters:
Frequency of the FM radio = 9.23 x 10⁷Hz
Velocity of the waves = 3 x 10⁸m/s
Unknown:
Wavelength of the wave = ?
Solution:
To solve for the wavelength of the wave, we need the velocity equation;
Velocity = frequency x wavelength.
Radio waves are all electromagnetic radiations produced by both electrical and magnetic fields perpendicularly oriented to one another.
Since the unknown is wavelength, we solve for it:
3 x 10⁸ = 9.23 x 10⁷ x wavelength
wavelength = 
wavelength = 3.2m
Answer:
280 N
Explanation:
acceleration = v2-v1 / time taken = (2-4 )/ 0.05 = -40 m/s^2 ( neg sign indicates slowing down )
force exerted = ma = 7 kg x -40 m/s^2 = - 280 N ( neg sign means opposite direction of initial velocity )
since the 7 kg ball is slowing down, the direction of force will be opposite of the initial velocity , and it will be 280 N