Answer:
A
Explanation:
<em>The gold used in the making of jewelry is usually not pure but a heterogeneous mixture of metals. Pure gold is quite soft and even though it may look better in appearance compared to those made using heterogeneous mixtures, it usually bends easily. Hence, in order to make the jewelry more durable, gold is usually mixed with other metals to form a heterogeneous mixture. </em>
The correct option is A.
 
        
                    
             
        
        
        
Answer:
A. At warm tempetures, molecules move around more. 
Explanation:
I'm at k12 and I just took the test got it right. Physical Science: Unit 2 Test
 
        
                    
             
        
        
        
Answer:
C is halved
Explanation:
The frequency and the wavelength of a wave are related by the equation:

where
v is the speed of the wave
f is the frequency
 is the wavelength
 is the wavelength
From the equation above, we see that for a given wave, if the wave is travelling in the same medium (and so, its speed is not changing), then the frequency and the wavelength are inversely proportional to each other.
Therefore, if the frequency doubles, the wavelength will halve in order to keep the speed constant:

 
        
             
        
        
        
The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number. Therefore, it is true!
 
        
                    
             
        
        
        
The uniform microwave radiation remaining from the Big Bang.
So, your body is always having background radiation and that means space!