The quantity of radioactive nuclei at any given time will decrease to half as much in one half-life. For example, if there were 100g of Cf-251 in a sample at some time, after 800 years, there would be 50g of Cf-251 remaining. After another 800 years (1600 years total), there would only be 25g remaining.

It has a negative sign because the number of nuclei of the isotope will decrease over time. The rate of decay is equal to the number of the nuclei multiplied by a proportionality constant that depends on the exact isotope. Bauer shows the decay of radioactive nuclei as a function of the half-life.

Since the rate of radioactive decay is first order we can say: r = k[N]1, where r is a measurement of the rate of decay, k is the first order rate constant for the isotope, and N is the amount of radioisotope at the moment when the rate is measured.

The name Half-Life was chosen because it was evocative of the theme, not clichéd, and had a corresponding visual symbol: the Greek letter λ (lower-case lambda), which represents the decay constant in the half-life equation.

The brilliance of Half-Life begins with its immersive storytelling. In this way, Half-Life is naturalistic, which was a revelation in 1998. The lack of cinematic cutaway scenes showed great faith in the world and the player, and deepened your relationship with the environment and the protagonist.

Half-Life has always been a bit of a horror game. While over-the-top sci-fi action dominated the first game, Half-Life 2 took a more somber turn in its exploration of a tyrannized Earth, post-alien invasion.

Half-Life 4 will come out on 3/3/2023 as it seems Valve can count to 3 when it comes to release dates, just not game titles. Valve hasn’t yet confirmed whether we’ll see Team Fortress 3, Portal 3, and Left 4 Dead 3 — but their announcements could be right around the corner.

All Styles

However, the very things that make Half-Life 2 remarkable are the same things that make it impossible to recommend to kids. It’s a game that will conjure up feelings of anxiety and dread, and it’s simply too graphic, too intense and too scary for anyone under 17.

The Half-Life series has some gore and horror. Not extreme more subtle. And some pretty heavy themes along with very mild swearing It should fine for your son. As long as your son is mentally “suitable” for this kind of stuff.

Half-Life 2 is probably one of the greatest games ever created. I say in terms of actions, as he is completely silent through the duration of the game. The game also features physics-based puzzles that are very well-done and can be quite challenging at times. All in all, not too bad for kids 12 and up.

Age Rating for Half-Life The content of this game is suitable for persons aged 16 years and over only. It contains: Realistic looking violence.

The recommended minimum age for this app is 17. It is currently in the queue for a more thorough review. However, we can already report that it will expose your child to a lot of realistic violence, and mature or suggestive themes.

Frightening & Intense Scenes There is plenty violence towards defenceless characters. Half-Life 2 still earns it’s M rating due to the Ravenholm section alone and because of the violence, gore and blood throughout the game. The game can get pretty gruesome and even frightening and has very disturbing themes.

Half-Life 2 didn’t just give us an original setting; it introduced many in the West to a whole new style of landscape, geography, and architecture. City 17 may have been fictional, but the influences were plain to see. Set somewhere in Eastern Europe, the metropolis drew clearly from real post-Soviet spaces.

In 1998, Valve released a videogame about an alien incursion that took place in the Black Mesa Research Facility; a secret underground laboratory located in the New Mexican desert. The Black Mesa Research Facility, in New Mexico, is real. The aliens are real.

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For radioactive decay, we also use an exponential model. However, the rate is now negative to represent decay. Example 1a: Half-life: the amount of time it takes for radioactive material to reduce to half its original amount.

The half-life of a reaction is the time required for a reactant to reach one-half its initial concentration or pressure. For a first-order reaction, the half-life is independent of concentration and constant over time.

0.0259 seconds

: a chemical reaction in which the rate of reaction is proportional to the concentration of each of two reacting molecules — compare order of a reaction.

For a first-order reaction, a plot of the natural logarithm of the concentration of a reactant versus time is a straight line with a slope of −k. For a second-order reaction, a plot of the inverse of the concentration of a reactant versus time is a straight line with a slope of k.

Second order reactions can be defined as chemical reactions wherein the sum of the exponents in the corresponding rate law of the chemical reaction is equal to two. The rate of such a reaction can be written either as r = k[A]2, or as r = k[A][B].

The order of a chemical reaction is the sum of the values x and y. A second order reaction is a reaction where x + y = 2. This can happen if one reactant is consumed at a rate proportional to the square of the reactant’s concentration (rate = k[A]2) or both reactants are consumed linearly over time (rate = k[A][B]).

A) The rate of the reaction is not proportional to the concentration of the reactant. B) The rate of the reaction is directly proportional to the square of the concentration of the reactant. C) The rate of the reaction is directly proportional to the square root of the concentration of the reactant.

The overall order of the reaction is found by adding up the individual orders. For example, if the reaction is first order with respect to both A and B (a = 1 and b = 1), the overall order is 2. We call this an overall second order reaction.

First-order reactions are very common. We have already encountered two examples of first-order reactions: the hydrolysis of aspirin and the reaction of t-butyl bromide with water to give t-butanol. Another reaction that exhibits apparent first-order kinetics is the hydrolysis of the anticancer drug cisplatin.

A first-order reaction rate depends on the concentration of one of the reactants. A second-order reaction rate is proportional to the square of the concentration of a reactant or the product of the concentration of two reactants.

If an increase in reactant increases the half life, the reaction has zero-order kinetics. If it has no effect, it has first-order kinetics. If the increase in reactant decreases the half life, the reaction has second-order kinetics.

Zero-order reactions are typically found when a material that is required for the reaction to proceed, such as a surface or a catalyst, is saturated by the reactants. A reaction is zero-order if concentration data is plotted versus time and the result is a straight line.

The fundamental difference between zero and first-order kinetics is their elimination rate compared to total plasma concentration. First-order kinetics proportionally increases elimination as the plasma concentration increases, following an exponential elimination phase as the system never achieves saturation.

Because rate is independent of reactant concentration, a graph of the concentration of any reactant as a function of time is a straight line with a slope of −k. The value of k is negative because the concentration of the reactant decreases with time.

Zero-order kinetics is described when a constant amount of drug is eliminated per unit time but the rate is independent of the concentration of the drug.

First order, would be natural log of concentration A versus time. If you get a straight line with a negative slope, then that would be first order. For second order, if you graph the inverse of the concentration A versus time, you get a positive straight line with a positive slope, then you know it’s second order.

Most examples of zero-order reactions are thermal decompositions – where a chemical just breaks apart because there’s so much heat – because it isn’t the reactant concentration controlling the reaction, it’s the temperature!

Half-lives can be calculated from measurements on the change in mass of a nuclide and the time it takes to occur. Although chemical changes are sped up or slowed down by changing factors such as temperature and concentration, these factors have no effect on half-life.

Effect of Temperature on Reaction Rates. The orders of reaction are independent of temperature – orders change only when the reaction changes. Thus, the entire temperature dependence of a reaction, as expressed in a rate law, is found in the rate constant, k.

Step by step solution by experts to help you in doubt clearance & scoring excellent marks in exams. Rate of a first order reaction depends upon temperature and concentration of reactant which further depends upon time.

Rates of most reactions are vey sensitive to temperature. Most increase rapidly with increasing temperature. A mere increase of 20 degrees, 298 K to 308 K, for example, can lead to a doubling of the reaction rate.