Answer:
When there remains one-quarter of the sample, the age of the sample is 10940 years
Explanation:
<u>Step 1:</u> Data given
The half-life of C-14 is 5470 years.
The half- life time is the time required for a quantity to reduce to half of its initial value.
This means after 5470 years there remains half of the C-14 sample.
To remain a quarter of the sample, another cycle of 5470 years is required.
This means 2 half-lives should have passed to remain a quarter of the sample.
<u>Step 2</u>: Calculate it's age
t/(t/1/2) = 2
⇒ with t = the age (or time) of the sample
⇒ with t(1/2) = the half-life time of the sample = 5470 years
⇒ with 2 = the number of halvf- lives passed
t/5470 = 2
t = 2*5470 = 10940 years
When there remains one-quarter of the sample, the age of the sample is 10940 years
Answer:
mass of sodium reacted is 184.1 g
Explanation:
mass Na = X = ?
∴ mass NaCl = 468 g
∴ mass Cl = 0.248 g
∴ molar mass NaCl = 58.44 g/mol
∴ atomic mass Cl = 35.453 a.m.u
∴ atomic mass Na = 22.989 a.m.u
⇒ moles Na = (X gNa)*(mol Na/22.989 g) = X/22.989 mol Na
⇒ mass NaCl = (X/22.989 mol Na)*(mol NaCl/mol Na)*(58.44 gNaCl/mol NaCl) = 468 g NaCl
clearing "X":
⇒ ((58.44)(X))/(22.989) = 468 g
⇒ X = 184.1 g = mass Na reacted
Answer:
Rust is a chemical reaction (oxidation) of iron that occurs over a period of time as the bare metal surface comes in contact with oxygen present in the air or water. Rust "eats" away the metal, rendering it weak and fragile. ... Avoid contact with water or moisture.
Answer:
A. air pressure,this is answer.
