What is exchanged between producers and consumers in an ecosystem?

What are Storm clouds? how are they different from other types of clouds?

goblinko [34]

Cumulus, stratus, and cirrus, there's many more but these are the main ones ^^

5 0

3 years ago

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What's the mass if a nickel

Mashutka [201]

58.6934 +/- 0.0002 u

8 0

3 years ago

The half-life of a radioactive isotope is the amount of time it takes for a quantity of that isotope to decay to one half of its

Sedaia [141]

Radio active decay reactions follow first order rate kinetics.

a) The half life and decay constant for radio active decay reactions are related by the equation:

$t_{\frac{1}{2}} =$ $\frac{ln 2}{k}$

$t_{\frac{1}{2}} = \frac{0.693}{k}$

Where k is the decay constant

b) Finding out the decay constant for the decay of C-14 isotope:

$Decay constant (k) = \frac{0.693}{t_{\frac{1}{2}}}$

$k = \frac{0.693}{5230 years}$

$k = 1.325 * 10^{-4} yr^{-1}$

c) Finding the age of the sample :

35 % of the radiocarbon is present currently.

The first order rate equation is,

$[A] = [A_{0}]e^{-kt}$

$\frac{[A]}{[A_{0}]} = e^{-kt}$

$\frac{35}{100} = e^{-(1.325 *10^{-4})t}$

$ln(0.35) = -(1.325 *10^{-4})(t)$

t = 7923 years

Therefore, age of the sample is 7923 years.

3 0

3 years ago

If a substance has a half life of 58 years and starts with 500 g radioactive, how much remains radioactive after 30 years?

Vilka [71]

Answer:

A = 349 g.

Explanation:

Hello there!

In this case, since the radioactive decay kinetic model is based on the first-order kinetics whose integrated rate law is:

$A=Ao*exp(-kt)$

We can firstly calculate the rate constant given the half-life as shown below:

$k=\frac{ln(2)}{t_{1/2}} =\frac{ln(2)}{58year}=0.012year^{-1}$

Therefore, we can next plug in the rate constant, elapsed time and initial mass of the radioactive to obtain:

$A=500g*exp(-0.012year^{-1} *30year)\\\\A=349g$

Regards!

5 0

3 years ago

The half life of radon-222 is 3.8 days. How Much of a 100g sample is left after 15.2 days

professor190 [17]

Answer:

6.2 g

Explanation:

In a first-order decay, the formula for the amount remaining after n half-lives is

$N = \frac{N_{0}}{2^{n}}$

where

N₀ and N are the initial and final amounts of the substance

1. Calculate the number of half-lives.

If $t_{\frac{1}{2}} = \text{3.8 da}$

$n = \frac{t}{t_{\frac{1}{2}}} = \frac{\text{15.2 da}}{\text{3.8 da}}= \text{4.0}$

2. Calculate the final mass of the substance.

$\text{N} = \frac{\text{100 g}}{2^{4.0}} = \frac{\text{100 g}}{16} = \text{6.2 g}$

4 0

3 years ago