Answer:
Sodium - malleable, soft, and shiny
Silicon - has properties of both metals and nonmetals
Bromine - highly reactive gas
Argon - non-reactive gas
Explanation:
Sodium is an alkaline metal. Just like other alkaline metals, it's malleable, soft, and shiny.
Silicon is a metalloid. Metalloids are elements that have properties of both metals and nonmetals.
Bromine a highly reactive chemical element. It is a fuming red-brown liquid at room temperature that evaporates to form a similarly coloured gas.
Argon is a noble gas. Just like other noble gases, it's non-reactive.
 
        
             
        
        
        
Answer:
54 days
Explanation:
We have to use the formula;
0.693/t1/2 =2.303/t log Ao/A
Where;
t1/2= half-life of phosphorus-32= 14.3 days
t= time taken for the activity to fall to 7.34% of its original value
Ao=initial activity of phosphorus-32
A= activity of phosphorus-32 after a time t
Note that;
A=0.0734Ao (the activity of the sample decreased to 7.34% of the activity of the original sample)
Substituting values;
0.693/14.3 = 2.303/t log Ao/0.0734Ao
0.693/14.3 = 2.303/t log 1/0.0734
0.693/14.3 = 2.6/t
0.048=2.6/t
t= 2.6/0.048
t= 54 days
 
        
             
        
        
        
The answer is TRUE.
If the Energy is on the left, then the problem is true. If it is on the right then it would be negative, false, and considered as exothermic.
Endothermic reaction = the products are higher in energy than the reactants.
Exothermic reaction = a chemical reaction that releases energy by light or heat.
        
                    
             
        
        
        
Second one i think.......
        
             
        
        
        
Answer:
Explanation: Ammonia (NH3) is produced by the reaction of nitrogen gas and hydrogen gas. ... How many grams of fluorine gas are needed to produce 100.00g of AlF3? ... How many molecules of CO2 gas can be produced of 156.24g of benzene, ... (a) If 16.74.g of Fe and 9.0 9 of H2O are allowed to react, how many grams of products.