The order of particle in all substance is the same A True B false

The radioactive substance cesium-137 has a half-life of 30 years. The amount At (in grams) of a sample of cesium-137 remaining a

stealth61 [152]

Answer: The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g

Explanation:

We are given a function that calculates the amount of sample remaining after 't' years, which is:

$A_t(t)=458\times (\frac{1}{2})^{\frac{t}{30}$

For t = 20 years

Putting values in above equation:

$A_t(t)=458\times (\frac{1}{2})^{\frac{20}{30}$

$A_t(t)=288.522g$

Hence, the amount of sample left after 20 years is 288.522 g

For t = 50 years

Putting values in above equation:

$A_t(t)=458\times (\frac{1}{2})^{\frac{50}{30}$

$A_t(t)=144.26g$

Hence, the amount of sample left after 50 years is 144.26 g

6 0

3 years ago

Classify water as proton donor or proton acceptor with reactions???

olasank [31]

Answer: It should a accepter

Explanation: because water is often used as solvent for solutes...there are exceptions

4 0

3 years ago

How many elements are there

Levart [38]

Answer:

there r 118 elements in periodic table..

hope it helps.

6 0

3 years ago

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How many total atoms are in 0.670 g of p2o5?

scoray [572]

The molecular formula for compound is $P_{2}O_{5}$ mass of compound is 0.670 g.

To calculate number of atoms first calculate number of moles in the compound as follows:

$n=\frac{m}{M}$

Molar mass of $P_{2}O_{5}$ is 283.886 g/mol, thus,

$n=\frac{0.670 g}{283.886 g/mol}=0.00236 mol$

Thus, number of mole of $P_{2}O_{5}$ is 0.00236 mol.

From the molecular formula 1 mole of $P_{2}O_{5}$ has 2 mol of P (phosphorus) and 5 mol of O (oxygen).

Thus, number of moles of P and O in 0.00236 mol of $P_{2}O_{5}$ will be:

$n_{P}=2\times 0.00236 mol=0.00472 mol$

Similarly,

$n_{O}=5\times 0.00236 mol=0.0118 mol$

Now, in 1 mol of an element there are $6.023\times 10^{23}$ atoms.

Number of atoms of P will be:

$N_{P}=0.00472\times 6.023\times 10^{23}=2.84\times 10^{21}atoms$

Similarly, number of atoms of O will be:

$N_{O}=0.0118\times 6.023\times 10^{23}=7.11\times 10^{21}atoms$

Total number of atoms will be sum of number of atoms of P and O:

$N_{Total}=N_{P}+N_{O}=2.84\times 10^{21}+7.11\times 10^{21}=9.95\times 10^{21} atoms$

Therefore, total number of atoms in $P_{2}O_{5}$ will be $9.95\times 10^{21} atoms$ .

8 0

3 years ago

A force of 350 N causes a body to move with an acceleration of 10 m/s2. What's the mass of the body?

Scrat [10]

You have to use the equation F=ma and solve for m to get m=F/a.
m=mass in kg
F=force (in this case 350N)
a=acceleration (in this case 10m/s²)
when you plug everything in you should find that m=35kg

I hope this helps.

3 0

3 years ago

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The order of particle in all substance is the sameA TrueB false​

The order of particle in all substance is the sameA TrueB false