6.76 x 10^11
this is because when you are placing something in a scientific notation you basically move the decimal place behind the last hole number in this case 6. and count the remaining  numbers behind the decimal such as .76,000,000,000 which there 11 counting 76 with the zeros. then you place the number of places behind the decimal as an exponent of 11 and keep all real numbers besides 0 as your other half
        
             
        
        
        
The answer is going to be 0.1775
        
                    
             
        
        
        
After 1 hour, 360 g decays to 180 g.
After another hour (total 2 hours), 180 g decays to 90 g.
After another hour (total 3), 90 g decays to 45 g.
After one more (total 4), 45 g decays to 22.5 g.
More quickly, with a half-life of 1 hour, the 360 g of starting material decays to
(360 g) / 2⁴ = 22.5 g
In general, if the half-life is 1 hour, then after <em>n</em> hours, an initial amount <em>A</em> of this substance decays according to
<em>A</em> / 2<em>ⁿ</em>