Answer:
The structure of the atom. 
Explanation:
The correct answer is - The structure of the atom. 
Reason -
An atom is the smallest unit of matter that retains all of the chemical properties of an element.
 
        
             
        
        
        
Answer:
The total time that Jim needs to change x oil changes and y tire changes is less than 180 min.
The time needed for x oil changes is 12 * x.
The time needed for y tire changes is 18 * y.
The total time is the sum of the above times and needs to be less than 180 that is
12 * x + 18 * y < 180 divide both sides of equation by 6
12/6 * x + 18/6*y < 180/6
2*x + 3*y < 30
2*x < 30 - 3*y divide both sides by 2 to get the inequality for x 
x < 30/2 - 3/2*y = 15 - 1.5 y < 15 that is x < = 15
2*x + 3*y < 30
3*y < 30 - 2*x divide both sides by 3 to get the inequality for y 
y < 30/3 - 2/3 *x = 10 - 2/3*x < 10 that is y < = 10
Also we can write x + y < x+ 3/2 * y < 15. 
Explanation:
Jim's can do not more then 5 oil changes and not more then 10 tire changes or all together she can do not more then 15 total of oil and tire changes.
 
        
             
        
        
        
..........The answer is B
        
             
        
        
        
Answer:
Physical properties can be observed, described, and measured without changing the material. ... To find the volume of a solid, pour liquid in a graduated cylinder and let a solid object sink in the liquid and measure how much volume is in the solid