Answer : The age of the rock is, 2.60 billion years
Explanation :
Half-life = 1.3 billion years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = ?
a = initial amount of the reactant = 12 mg
a - x = amount left after decay process = 3 mg
Now put all the given values in above equation, we get
Therefore, the age of the rock is, 2.60 billion years
Answer:
electrons are negatively charged and are located in the electron cloud (outside the nucleus)
Answer: 41.46 L
Explanation:
La ecuación que describe relación entre presión, volumen, temperatura y la cantidad (en moles)
de un gas ideal es:
PV = nRT
Donde: P = Presión absoluta
, V= Volumen , n = Moles de gas
, R = Constante universal de los gases ideales, T = Temperatura absoluta,
R = 0.082 L. atm/mol. °K
V = nRT/P
Calculanting n
n = mass/ molecular mass
<h3>n = 4 g / 2g. mol⁻¹</h3><h3>n = 2 mol</h3><h3>T =25⁰ + 273 ⁰K = 298 ⁰K</h3><h3>V = (2 mol ₓ0.082 L. atm / mol.°K x 298 ⁰K) / 1.18 atm = 41.46 L</h3>
The right answer is screening test.
In medicine, screening consists of looking for one or more diseases or abnormalities known as "at risk" in individuals of a given population.
These investigations are followed or not by medical consultations, clinical examinations and treatments.
In addition, screening is a preliminary procedure (test or examination) to detect one or more characteristic signs or symptoms of a disease or syndrome and potentially leading to further investigation.
Answer:
e. 81.0%
Explanation:
Morphine has Molar mass = 285.34 g/mol
Also, number of males of Morphine = Number of moles of HCl
(At equivalence point )
Now, number of moles of HCl = Molarity × volume
=0.01 mol × 2.84×10^(-3) L
= 2.84×10^(-5) mol
therefore number of moles of morphine= 2.85×10^(-5)
Mass of Morphine= No. of moles × molar mass
= 2.84×10^(-5)×285.34 g/mol
= 0.0081 g
= 8.1 mg
therefore
percentage of morphine = mass of morphine/ mass of powder×100%
= 8.1/10×100% = 81.0%
hence option e is correct.