Answer:
It should be used 2 digits to the right of the decimal point to report the result
Explanation:
When adding or subtracting two decimal numbers, the number of digits to the right of the decimal point in the result is equal to the amount with the least number of decimal places.
In this case we have 4 decimal places in 0.0136 g, 2 decimal places in 2.70 × 10-4 g and 2 decimal places in 4.21 × 10-3 g, so, the least number of decimal places is 2 and that should be the number of digits to the right of the decimal point in the result.
Then the result of the sum should be 9.66 × 10-3 g
I got 2.......................
The solutions having pOH=3.37, [h+]=3.8x10^-4 and pH=5.11 are acidic. Solutions with pOH=11.40, [OH-]=6.6x10^-3 and pH=12.94 are basic. The solution with [h+]=1.0x10^-7 is neutral. The solutions with [h+]=5.8x10^-8 and [OH-]=3.5x10^-12 are mildly acidic and basic respectively.
In an aqueous solution at 25 °C, the pH and pOH scales are defined so that water, which is neutral, has a pH of 7.00 and a pOH of 7.00. If the pH is less than 7, the solution is acidic. If the pH is greater than 7, the solution is basic. Hence, solutions with pOH=3.37 and [h+]=3.8x10^-4 are acidic, as they would have a pH lower than 7. The solutions with pOH=11.40, [OH-]=6.6x10^-3 and pH=12.94 are basic, as they would have a pH higher than 7. The solution with [h+]=1.0x10^-7 is neutral as it has a pH of 7. The solutions with [h+]=5.8x10^-8 and [OH-]=3.5x10^-12 are slightly acidic and basic respectively due to being close to the pH of 7. The solution with pH=5.11 is acidic as it's less than 7.
#SPJ12
The given solutions can be classified based on pH, pOH, [H+] and [OH-]. Based on these values, they are categorised as acidic, basic, or neutral.
The values provided are measures of the concentration of Hydronium ions [H+], hydroxide ions [OH-], pH, and pOH, which help determine whether a solution is acidic, basic, or neutral. At 25 degrees Celsius, a neutral solution has pH = 7, pOH=7, [H+] = 1.0x10^-7, and [OH-] = 1.0x10^-7. If the pH or [H+] is less than 7, or pOH or [OH-] is greater than 7, the solution is acidic. If the pH or [H+] is greater than 7, or pOH or [OH-] is less than 7, the solution is basic.
Applying this for each solution: pOH=3.37, acidic; pOH=11.40, basic; [H+]=3.8x10^-4, acidic; [H+]=5.8x10^-8, acidic; [OH-]=3.5x10^-12, acidic; [OH-]=6.6x10^-3, basic; [H+]=1.0x10^-7, neutral; pOH=7, neutral; pH=5, acidic; pH=12.94, basic.
#SPJ11
the neutron and the electron cloud
O the neutron and the proton cloud
O the nucleus and the electron cloud
Answer:
the nucleus and electron cloud is the correct option
The answer is: 3) 7.64 days.
The most stable isotope of radon (Rn) is radon-222 with a half-life of 3.82 days.
After first half life (3.82 days) = 0.5 · 200 g.
After first half life (3.82 days) = 100 g of radon-222.
After second half life (7.64 days) = 0.5 · 100 g.
After second half life (7.64 days) = 50 g of radon-222.
Half-life is the time required for a quantity (in this example number of radioactive nuclei of radon-222) to reduce to half its initial value and is independent of initial concentration.