Help????? You need to write as if you are Dmitri Mendeleev and you have just made your proposed version of the periodic table. You need to write to the Royal Society of Chemistry in London explaining:
• Who you are
• What your periodic table is like, the groups, elements and features
• Why you think your periodic table is correct
• How you have built on the work of others or why you think their work is not
correct
Ca^2+ and I^-
Na+ and Co3^2-
Ga^3+ and ClO3
Cu^2+ and F-
NH4^- and PO4^3-
Fe2+ and (SO4)^2-
Mg2+ and NO3^-
NH4^+ and NO2^-
K^+ and (C2H3O2)^- {C2H3O2 is acetate}
Na^+ and Cr2O7^2-
This is an incomplete question, here is a complete question.
The conversion of cyclopropane to propene occurs with a first-order rate constant of 2.42 × 10⁻² hr⁻¹. How long will it take for the concentration of cyclopropane to decrease from an initial concentration 0.080 mol/L to 0.053 mol/L?
Answer : The time taken will be, 17.0 hr
Explanation :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial concentration of the reactant = 0.080 M
a - x = concentration left = 0.053 M
Now put all the given values in above equation, we get


Therefore, the time taken will be, 17.0 hr
Answer:
The length of the fence is 22.5ft and the width of the fence is 7.5ft.
Explanation:
To solve this problem we will turn this question into an equation.
The equation for the perimeter of a rectangle is 2l + 2w = perimeter.
In the question we were given the perimeter so we can go ahead and plug this in.
2l + 2w = 60
In the question we are also told that the fence is 3 times as long as it is wide. This means that 1l = 3w. We can now subsitute l for 3w so that we only have one variable.
2(3w) + 2w = 60
Now we can simply use algebra to solve for w.
6w + 2w = 60
8w = 60
w = 7.5
Now that we know the value of w we can find the value of l since we know 1l = 3w.
l = 3w
l = 3(7.5)
l = 22.5
The length of the fence is 22.5ft and the width of the fence is 7.5ft.