Answer:
Here's what I get
Step-by-step explanation:
The atomic model before Chadwick
J. J. Thomson had discovered the electron in 1897 and Rutherford discovered the proton in 1912.
So, in the 1920s, scientists thought that a helium atom (₂⁴He), for example, consisted of four protons, two electrons orbiting the nucleus, and another two electrons in the nucleus to balance the charge.
In 1932, Irène and Frédérick Joliot-Curie discovered that when α particles hit a Be target, a strange radiation was emitted that could knock protons out of paraffin. They thought it was some type of high-energy X-rays
Chadwick's experiment
Chadwick thought the radiation consisted of particles, not X-rays. He repeated the Curie's experiment and carefully measured the velocities of the scattered protons.
Using the Laws of Conservation of Energy and Momentum, he calculated that the radiation hitting the paraffin must consist of neutral particles with a mass slightly greater than that of a proton.
Chadwick had discovered the neutron.
The atomic model after Chadwick
Chemistry now made more sense. A helium atom now consisted of two electrons orbiting a nucleus containing two protons and two neutrons. There was no need to have electrons in the nucleus.
Answer:
The answer is c
Step-by-step explanation:
Answer: the fourth choice: <span>No, the addition symbol was dropped in the second expression
Justification:
1) The right operation is: </span><span>(4.5m + 7/8) - 9 </span><span>= 4.5m + (7/8 - 9), this is you have to keep the + operator, since you are just grouping the terms in an alternate form.
2) Droping the + operator leads incorrectly to the multiplication of the first term, 4.5m to the terms in parenthesis, instead to the addition, which is what corresponds.
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Answer:
Step-by-step explanation:
2x^3y and 2yx are not like terms since x^3 can't be added to x since it's not x^3 but x^2.
Answer:
The answer in the attached figure
Step-by-step explanation:
we have
The graph of this equation is a straight line
The domain is all real numbers
The range is all real numbers
Step 1
Find the value of y for 
Substitute the value of x in the equation and solve for y



The ordered pair is the point 
Step 2
Find the value of y for 
Substitute the value of x in the equation and solve for y



The ordered pair is the point 
Step 3
Find the value of y for 
Substitute the value of x in the equation and solve for y



The ordered pair is the point 
Step 4
Plot the ordered pairs


see the attached figures