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How many atoms are lefr not decayed in a 500 atom sample after 60 minutes if the half life is 20 minutes?
The half-life of the sample is 20 minutes, meaning that after each 20-minute interval, half of the remaining atoms will have decayed. After 60 minutes, which is three half-lives, the number of remaining atoms can be calculated as follows:
- After 20 minutes: 500 / 2 = 250 atoms
- After 40 minutes: 250 / 2 = 125 atoms
- After 60 minutes: 125 / 2 = 62.5 atoms
Since we cannot have a fraction of an atom, we round down to 62 atoms remaining after 60 minutes.
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The atomic mass of an atom is the?
The atomic mass of an atom is the mass of 6.011 X 10^23 atoms of that element.
What is the number 4 in SiCl4?
In SiCl4, the number 4 indicates that there are four chlorine (Cl) atoms bonded to a single silicon (Si) atom. The compound is silicon tetrachloride, which is named for the four chlorine atoms. This tetrahedral arrangement around the silicon atom is typical for compounds with a central atom bonded to four other atoms.
What is the ratio of mgbr2?
The ratio of magnesium bromide (MgBr₂) consists of one magnesium (Mg) atom to two bromine (Br) atoms. This means that for every one magnesium atom, there are two bromine atoms, resulting in a 1:2 ratio. In the compound, the subscript '2' indicates that there are two bromine atoms for each magnesium atom.
How much of radioactive substance remains after 15 hours if it's half life is 5 hours?
The half-life of a radioactive substance is the time that it takes for half of the atoms to decay. With a half-life of 10 days, half has decayed in this time. After 20 days, a further 10 days/another half life, a further half of the remainder has decayed, so 1/4 of the original material remains, 1/4 of 15g is 3.75 grams. This is the amount of original radioactive substance remaining, but it’s daughter isotope ( what the decay has produced ) is also present, so the original sample mass is effectively constant, especially in a sealed container. Even in an unsealed container, and assuming alpha ( helium nucleii) emission, a drop in mass per radioactive atom of 4 Atomic Mass units, compared with the original atom of, say 200 amu is only 2% mass decrease, less for heavier decaying nucleii.
What is the set ratio of h2o?
2 atoms of hydrogen to 1 atom of oxygen.
How many atom of a 1.0 mole sample of bismuth 214 will remain after 20 minutes?
All radio active reactions are of first order reactions , for those first order reactions rate constant , k = 0.693 / t 1/2 : t 1/2 = half life of Bi is = 19.7 min So k = 0.693 / 19.7 = 0.0352 min -1 For a first order reaction rate constant , K = ( 2.303/t)x log (a / ( a-x) ) Where a = initial atoms = 6.023x10 23 atom / mol a-x = atoms left after time t = ? t = time = 20 min Plug the values we get log (a / ( a-x) = kt / 2.303 = ( 0.0352x20 ) / 2.303 = 0.305 a / (a-x) = 10 0.305 = 2.02 (a-x) = (6.023x10 23 ) / 2.02 = 2.98 x 10 23 atoms
The actual mass of an atom of argon is is 6.63x10-24g How many atoms are in a 40.0-g sample of argon?
To find the number of argon atoms in a 40.0-g sample, you first need to calculate the number of moles of argon in the sample using the molar mass of argon (39.95 g/mol). Then, you can use Avogadro's number (6.022x10^23 atoms/mol) to determine the number of atoms in that many moles of argon.
How many atoms are in limestone and what kinds?
Limestone primarily consists of calcium carbonate (CaCO₃), which contains three types of atoms: calcium (Ca), carbon (C), and oxygen (O). Each formula unit of calcium carbonate contains one calcium atom, one carbon atom, and three oxygen atoms, totaling five atoms. The exact number of atoms in a sample of limestone will depend on the sample's size and the amount of calcium carbonate it contains.
How many C-13 atoms are present on average in a 13000-atom sample of carbon?
Carbon-13 make up 1.1% of carbon atoms. .011 x 19000 carbon atoms = 209 carbon-13 atoms present.
A sample of nitric acid contains 50 HNO3 molecules How many oxygen atoms are in this sample?
In each nitric acid molecule (HNO3), there is one oxygen atom. So, in a sample containing 50 HNO3 molecules, there would be 50 oxygen atoms.
How many atoms does bohrium have?
Your question does not make sense. One sample of bohrium could have a certain amount of atoms, while another sample of bohrium may have a different number of atoms. You probably mean: How many protons does bohrium have? Although it is synthetic and radioactive, a bohrium atom can be retained for a few seconds. It then has 107 protons.
The half-life of a radioactive element is?
The time it takes for half of the atoms to decay, and become some other type of atom.
What does the formula indicate about the composition of a 1.0 gram sample of hydrogen sulfide?
All of the molecules are identical combinations of two hydrogen atoms and one sulfur atom.
What does half-life of a radioactive sample mean?
It means that after the specified time, half the atoms will have broken apart - converting into some other kind of atom.It means that after the specified time, half the atoms will have broken apart - converting into some other kind of atom.It means that after the specified time, half the atoms will have broken apart - converting into some other kind of atom.It means that after the specified time, half the atoms will have broken apart - converting into some other kind of atom.
The way you express the time it takes for atoms in a radioactive substance to distintegrate is called?
The time used for dealing with nuclear decay is called a half life. Decay of a radioactive atom is something that happens by change, and the atoms of one isotope may be more or less prone to decay than the atoms of another. The way we normally express the rate of decay is to speak of the amount of time it takes for half of the atoms in a sample to decay, which is the same as the time during which any one atom of the sample has a 50% chance of decaying.
How many atoms are in chalk?
Chalk primarily consists of calcium carbonate (CaCO₃). A single formula unit of calcium carbonate contains five atoms: one calcium (Ca) atom, one carbon (C) atom, and three oxygen (O) atoms. To determine the total number of atoms in a sample of chalk, you would need to know the amount of chalk, but each formula unit consistently contains five atoms.
Do chemical formulas show the total number of atoms in a sample of a compound?
Yes, chemical formulas show the number of atoms in a compound. Water is H2O -- two hydrogen atoms bonded to one oxygen atom. Carbon dioxide is CO2 -- one carbon and two oxygen atoms.
