Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
Answer:
去無奈此刻投哦他家
Explanation:
pH=3 المحلول حمضي او قاعده
The suffix -ene tells that there is a double bond present in the molecule, and the 2 tells where in the molecule the bond is located. The molecule looks like this:
CH3-CH=CH-CH3
-ane indicates single bonds
-ene indicates at least one double bond
-yne indicates at least one triple bond
Answer:
Functional group
Explanation:
Functional group is specific group of atom or bond associated to an organic compound that determines the chemical properties of that compound. This atom is bonded in a certain way or specific arrangement to give the compound a peculiar physical and chemical characteristics.
Functional group like the alkyl group -CH3 is found in organic compound series like the alkane family. The chemical properties specific to the alkyl group will be active in the compound of alkane family because of the presence of the functional group Alkyl(-CH3). The functional group also plays a major role in the chemical reactivity of the compound. For example the functional group of alkyl are often non reactive, this non reactive nature will definitely rub off on the chemical properties of the compound it is attached.
Functional group like -OH is usually found in Alcohol . Due to the presence of this functional group (-OH) alcohol possess a peculiar chemical properties. The compounds possess an hydrogen bond which invariably lead to the higher boiling points of the alcohol compounds. Other functional group can be bonds like double bond found in alkene compound or triple bond found in alkyne compound.
