The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
Answer:
When copper(II) chloride and sodium carbonate solutions are combined, solid copper(II) carbonate precipitates, leaving a solution of sodium chloride. Write the conventional equation, total ionic equation, and net ionic equation for this reaction.
Explanation:
The word equation for the reaction is:
Copper (II) chloride(aq) + sodium carbonate (aq) ->sodium chloride (aq) + copper carbonate(s)
The balanced chemical equation of the reaction is:

The complete ionic equation is:

The net ionic equation is obtained from the complete ionic equation after removing the spectator ions:

Answer:
a. 
b. K = 192.9
c. Products are favored.
Explanation:
Hello!
a. In this case, according to the unbalanced chemical reaction we need to balance HCl as shown below:

In order to reach 2 hydrogen and chlorine atoms at both sides.
b. Here, given the concentrations at equilibrium and the following equilibrium expression, we have:
![K=\frac{[HCl]^2}{[H_2][Cl_2]}](https://tex.z-dn.net/?f=K%3D%5Cfrac%7B%5BHCl%5D%5E2%7D%7B%5BH_2%5D%5BCl_2%5D%7D)
Therefore, we plug in the data to obtain:

c. Finally, we infer that since K>>1 the forward reaction towards products is favored.
Best regards!
Answer:
ionic compounds contain a metal and a non metal
covalent compounds contain only non metals
Explanation:
Each type of compound is named according to different rules.
A simply because of I'm a pretty good guesser, Hope this helps.