The given question is incomplete. The complete question is :
The thermal decomposition of phosphine (PH3) into phosphorus and molecular hydrogen is a first-order reaction: 
The half-life of the reaction is 35.0 s at 680°C. Calculate the first order rate constant.
Answer: a) The first order rate constant is 
b) The time after which 95% reactions gets completed is 151 seconds
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for finding the rate constant
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
The first order rate constant is
b) for completion of 95 % of reaction
The time after which 95% reactions gets completed is 151 seconds
Answer:
genes are small sections of DNA. These genes contain instructions that tell your cells to make molecules called proteins. And the protein do things to your body to keep you healthy. Genes determine traits as well.
Endothermic because the separation of the ions dictate the overall reaction
Most of the elements on the periodic table are metals...generally speaking...metals occur on the left side of the periodic table, and non-metals occur on the right side of the periodic table...
<span>...check out the periodic table locate at: http://www.elementsdatabase.com/ </span>
<span>look at the second colored periodic table...take a look at the key for this table...notice that the non-metals are colored white or red...all other elements would therefore be metals... </span>
Answer:
17
Two clear liquids mix and form a
white solid
18.chemical
A pot of water begins to
boil
19.Physical
the rest im usure on.
