Theyre temporary magnets, so they can be turned on and off.
Answer:
A chemical change is a change in the chemical makeup of a substance and results in a new substance. Ice and water both have the same chemical makeup - ice is just a different state and has the same atoms but in an expanded form.
Explanation:
substitute: <span><span>t<span>1/2</span></span>=<span><span>ln(2)</span>k</span>→k=<span><span>ln(2)</span><span>t<span>1/2</span></span></span></span>
Into the appropriate equation: <span>[A<span>]t</span>=[A<span>]0</span>∗<span>e<span>−kt</span></span></span>
<span>[A<span>]t</span>=[A<span>]0</span>∗<span>e<span>−<span><span>ln(2)</span><span>t<span>1/2</span></span></span>t</span></span></span>
<span>[A<span>]t</span>=(250.0 g)∗<span>e<span>−<span><span>ln(2)</span><span>3.823 days</span></span>(7.22 days)</span></span>=67.52 g</span>
Answer:
3.329 g
Explanation:
First you need to determine the molar mass of H2S which is 34.1 g/mol.
With that we know that to find the moles of H2S we just divide the mass of sample with the molar mass.
3.54 g / 34.1 g/mol = 0.103812317 mol of H2S
This means that there is also 0.103812317 mol of sulfur since there is 1 mole of sulfur per 1 mole of H2S.
The molar mass of sulfur is 32.065 g/mol and to find the mass of sulfur you need to multiply the molar mass with the moles of the compound.
0.103812317 mol * 32.065 g/mol = 3.329 g of sulfur
Let me know if you get something else or if something is unclear in the comments so that we can figure it out.
Answer:
The value is 
Explanation:
From the question we are told that
The molar mass of 
is 
The total mass is 
The uncertainty of the total mass is 
Generally the molar weight of calcium is 
The percentage of calcium in calcite is mathematically represented as
Generally the mass of each sample is mathematically represented as
Generally mass of calcium present in a single sample is mathematically represented as
The uncertainty of mass of a single sample is mathematically represented as
The uncertainty of mass of calcium in a single sample is mathematically represent
Generally the average mass of calcium in each sample is
