plz help!!!!!!!
the amount of carbon 14 present in a paint after t years is given by a(t)=a0 e-0.00012t. the paint contains 32% of its carbon 14. estimate the age of the paint. round to the nearest year as needed.
0.32 = e-0.00012tln 0.32 = -0.00012t-1.139 ≈ -0.00012t9495.29 ≈ t
generaloraverage rate is the change in the concentration of a compound over a period of time.the average rate the reactants and products in a reaction are equal when the coefficient for each is 1.the rate for the reactants are negative. this is because the reactants are being consumed in the reaction. the rate for the product c is positive because it is being produced in the reaction.for a reaction where the coefficients of the compounds are different, the rate is multiplied by the reciprocal of the coefficient.example: 2a + b → 3cthe given reaction is:3o2(g) → 2o3(g)­given the rate of o2 consumption is -2.17x10-5 mol/l∙snote that value is negative to indicate that it is decreasing as the reaction proceeds.rearranging the rate equation to give the reaction rate is terms of [o3]: on sapling its

oxidation:
cu --> cu^2+ + 2e^-

reduction:
o\_2 + 4e^- -->2o^2- i. given:valency of carbon is 4valency of chlorine is 1by applying criss-cross method:formula: ccl4thus, the formula for carbon tetrachloride is ccl4.ii. given:valency of element x is 1valency of oxygen is 2by applying criss-cross method:formula: x2o hii..

according to me,the cut off will be around 90-95 marks for general category,50-55 marks for obc category,35-40 marks for sc category and 25-30 marks for st category.so it is difficult to be predict now.

please see the table below for previous years trends:-

 

jee main cut off trends (2013-2017)

| s.no. | category | 2017 | 2016 | 2015 | 2014 | 2013 |
| 1 | general | 81 | 100 | 105 | 115 | 113 |
| 2 | obc-ncl | 49 | 70 | 70 | 74 | 70 |
| 3 | sc | 32 | 52 | 50 | 53 | 50 |
| 4 | st | 27 | 48 | 44 | 47 | 45 | The simple interest formula is:  
I = P*R*T, where   
I - interest, P - principal, R - rate, T - time in years of the loan.  
Then, R = I/(P*T) =140/(500*7) = 0.04  
The rate is 4% **Pure substance – ethyl alcohol, oxygen, carbon, distilled water mixture – blood, steel** <p>concepts and reason</p>
<p>the concept used to solve this problem is the formal charge calculation of the oxygen atoms present in the ozone molecule.</p>
<p>fundamentals</p>
<p>a charge that is assigned to an atom, which is present in the molecule, is represented as a formal charge. in two bonded atoms, a formal charge assumes that the electrons are equally shared between them. the formal charge is calculated using the following formula:</p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>here, \(\mathrm{v}\) is the number of valence electrons, \(\mathrm{n}\) is the number of non-bonding electrons and \(\mathrm{b}\) is the number of bonding electrons.</p>
<p> </p>
<p>the structure is as follows:</p>
<p>calculate the formal charge for the circled oxygen in ozone molecule as follows:</p>
<p><img src="https://img.wizedu.com/images/5af6d1f54822b4dfb8fe89d91ef2011c5fe3020815aa4.png" alt="" width="88" /></p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>\(\begin{aligned}=& 6-6-\frac{2}{2} \\ &=-1 \end{aligned}\)</p>
<p>explanation | common mistakes | hint for next step</p>
<p>the marked oxygen atom has 6 valence electrons. it contains 6 non-bonding electrons. the marked oxygen atom is bonded with one oxygen atom. therefore, the bonding electron of oxygen is \(2 .\) substitute the values in a formal charge formula to determine the formal charge of oxygen (marked).</p>
<p> </p>
<p>the structure is as follows:</p>
<p><img src="https://img.wizedu.com/images/39493056a8515708b79350d1976e17b35fe30216f0473.png" alt="" width="88" /></p>
<p>calculate the formal charge for the circled oxygen in ozone molecule as follows:</p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>\(=6-2-\frac{6}{2}\)</p>
<p>\(=+1\)</p>
<p>explanation | common mistakes | hint for next step</p>
<p>the oxygen atom in the middle has 6 valence electrons and has 2 non-bonding electrons. the central oxygen atom is bonded with 1 double bond and 1 single bond. so, there is a total of 3 bonds containing 6 electrons (bonding electrons). the formal charge of the middle oxygen atom can be determined by substituting the values in a formal charge formula.</p>
<p> </p>
<p>the structure is as follows:</p>
<p><img src="https://img.wizedu.com/images/b1122ce7723aa4ab1f9ae5c9e457299e5fe3022ca77a5.png" alt="" width="88" /></p>
<p>calculate the formal charge for the circled oxygen in ozone molecule as follows:</p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>\(=6-4-\frac{4}{2}\)</p>
<p>\(=0\)</p>
<p>the formal charge of each oxygen atom in \(\mathrm{o}\_{3}\) molecule are labeled as follows:</p>
<p><img src="https://img.wizedu.com/images/1de5ee227194f6d8c7fb9fb0e76160f25fe3024117fde.png" alt="" width="120" /></p>
<p>the oxygen atom present on the right side contains 6 valence electrons which have 2 non-bonded electrons. the marked oxygen is bonded with 1 double bond with a central oxygen atom. so, the number of bonding electrons is \(4 .\) the formal charge of the corner oxygen atom (right corner) can be determined by substituting the values in the formal charge formula.</p>
<p>the formal charge of each oxygen atom in \(\mathrm{o}\_{3}\) molecule are labeled as follows:</p>
<p><img src="https://img.wizedu.com/images/1de5ee227194f6d8c7fb9fb0e76160f25fe3024117fde.png" alt="" width="120" /></p> we’re being asked which of the following conditions occurs when a chemical change happens to a piece of wood let’s first define a physical change and a chemical change.physical change → there is a change in a matter as it goes from one physical state to another.chemical change → atoms rearrange themselves to create a new substance. now, let’s take a look at each condition:[readmore]a. is splitsplitting wood is only reducing its size. physical changeb. is paintedpainting wood is only placing paint on top of it and not really affecting the composition of the wood.  physical changec. decaysdecaying changes the integrity of the wood itself and transforms it into things like soil. chemical changed. is cutcutting wood is only reducing its size. physical changea chemical change occurs when a piece of wood c. decays. there are 2 pints in a quart. there are 4 quarts in a gallon. 1 quart = 2 pints the ratio of present ages of raman and salman is 4 : 5. after 5 years the ratio of ages of salman and karan will be 5 : 4. what is the difference (in years) in present age of raman and karan?रमन और सलमान की वर्तमान आयु का अनुपात 4 : 5 है। 5 वर्ष बाद, सलमान और करन की आयु का अनुपात 5 : 4 होगा। रमन और करन की वर्तमान आयु (वर्षों में) में अंतर कितना है?&nbsp;