Measuring the ratio of C-14 to C-12 in the remains of dead organisms to determine how much time has passed since the organism died
the answer is D
 
        
             
        
        
        
Chromium , silver, zinc...
        
                    
             
        
        
        
Answer:
She can add 380 g of salt to 1 L of hot water (75 °C) and stir until all the salt dissolves. Then, she can carefully cool the solution to room temperature.  
Explanation:
A supersaturated solution contains more salt than it can normally hold at a given temperature.
A saturated solution at 25 °C contains 360 g of salt per litre, and water at 70 °C can hold more salt.
Yasmin can dissolve 380 g of salt in 1 L of water at 70 °C. Then she can carefully cool the solution to 25 °C, and she will have a supersaturated solution.
B and D are wrong. The most salt that will dissolve at 25 °C is 360 g. She will have a saturated solution.
C is wrong. Only 356 g of salt will dissolve at 5 °C, so that's what Yasmin will have in her solution at 25 °C. She will have a dilute solution.
 
        
                    
             
        
        
        
Put the <em>wood and excess oxygen in a closed contai</em>ner that contains some device that can create a spark (to start the reaction).
Determine the <em>mass of container + contents</em>.
<em>Start the reaction</em> and, after everything has cooled down, again determine the <em>mass of container + contents</em>.
If the two masses are the same, you have demonstrated that the reaction obeys the Law of Conservation of Mass.
 
        
             
        
        
        
Answer: increasing frequency or energy and decreasing wavelength.
Explanation:
Electromagnetic wave is defined as the wave which is associated with both electrical and magnetic component associated with them. They can travel in vacuum as well and travel with the speed of light i.e  
The electromagnetic spectra consist of radio waves, microwaves, infrared ,Visible , ultraviolet, X rays and gamma rays arranged in order of increasing frequency or increasing energy and decreasing wavelengths.