The half-life of radioactive substance is 2.5 minutes. what fraction of the origional radioactive remains after 10 mins

Answers

Answer 1

Answer: The answer is 1/16.

Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1. $(1/2)^(n) = x$ ,
where:
n - a number of half-lives
x - a remained fraction of a sample

2. $t_(1/2) = (t)/(n)$
where:
$t_(1/2)$ - half-life
t - total time elapsed
n - a number of half-lives

So, we know:
t = 10 min
$t_(1/2)$ = 2.5 min

We need:
n = ?
x = ?

We could first use the second equation to calculate n:
If:
$t_(1/2) = (t)/(n)$ ,
Then:
$n = (t)/( t_(1/2) )$
⇒ $n = (10 min)/(2.5 min)$
⇒ $n=4$

Now we can use the first equation to calculate the remained fraction of the sample.
$(1/2)^(n) = x$
⇒ $x=(1/2)^4$
⇒ $x= (1)/(16)$

Related Questions

Which of the following will not have the same number of valence electrons?carbonsiliconleadbismuth
1.Cheraw is a folk dance native to Mizoram. True or False?2.Neon is used in electric signs and fluorescent lamps .true or false?
Is americium a solid, liquid or gas
What kind of glass is the following Si, O, Na, B, Al no plastic, no visible change, will shatters to high impact? 1. Pyrex Glass 2. Laminated soda-lime glass, 3. Ordinary Soda-Lime Glass, 4. Heat-tempered soda-lime glass?
Which two properties are used to define matter? A.has mass and conducts heat B.has buoyancy and volume C.has mass and takes up space D.conducts energy and has characteristic properties

Which phase of matter consists of particles that are held together but have the ability to flow past each other?

Answers

Explanation:

In solids, molecules are held together due to strong intermolecular force of attraction between them. These molecules do not move past each other as they are fixed at their position. As a result, solids have definite shape and volume.

In liquids, molecules are less tightly held as a result the molecules are able to move and hence they slide past each other. Liquids do not have fixed shape and volume.

In gases, molecules are held by weak Vander waal forces. Therefore, they move rapidly from one place to another with more collisions.

Thus, we can conclude that liquid is the phase of matter which consists of particles that are held together but have the ability to flow past each other.

liquid making it the correct answer

How many grams are in 2.4 moles of sulfur?

Answers

According to the mole concept, there are 76.94 g in 2.4 moles of sulfur atoms.

What is a mole?

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.

It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons. Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.

Mass is found out by number of moles by formula , mass=number of moles×molar mass

Substitution in above formula gives, mass=2.4×32.06=76.94 g

Thus, there are 76.94 g in 2.4 moles of sulfur.

Learn more about mole,here:

brainly.com/question/26416088

#SPJ6

Use the equation
Given molesX Molar Mass(g)/1 mol= Mass in grams
2.4 moles X 32.065/1
76.96 Grams :)

If the Kelvin temperature of a gas is tripled and the volume if doubled, the new pressure will be ___. A. 3/2 the original pressure B. 1/6 the original pressure C. 5 times the original pressure D. 2/3 the original pressurethe answer isnt b or c

Answers

The answer is 3/2 the original pressure. The concept behind this is the ideal gas law wherein it states that Pressure (P) times volume(V) is equal to number of moles (n) times ideal gas constant (R ) times temperature (T). Since you’re trying to calculate for the pressure you use P=nRT/V. Input 3 to Temperature and 2 to volume. You’ll get a pressure of 3/2 which is 3/2 times the original pressure.

A student wants to do scientific research on how nuclear fusion can be usedas a power source on Earth. What type of scientist does the student want to
become?

Answers

Answer:

A physicist

Explanation:

A physicist is one who deals with matter energy and how they are related

Write formula for these compounds: a. Sodium iodide b. Tin (II) chloride c. Potassium Sulfide d. Calcium iodide

Answers

All these compounds are ionic compounds and the formula of the compounds are: Tin(II) chloride - SnCl₂, potassium sulphide- K₂S, calcium chloride - CaCl₂.

What is chemical formula?

The chemical formula of a compound make them easy to identify the elements of composition. The formula of a compound s given with the chemical symbols of elements.

The subscripts of atoms is the number of that elements in the compounds. For instance, tin(II) chloride is formed by losing two electrons from the metal tin -Sn to each two chlorine atoms and thus the formula is SnCl₂.

Potassium sulphide is an ionic compound formed by losing one electrons from potassium to the sulphur atom. Sulphur needs two electrons to attain octet thus it binds with two K atoms and the formula is K₂S.

Calcium chloride is formed by the ionic bonding between calcium and chlorine atom. Calcium has the valency of two thus, it donates two electrons each to each chlorine atoms and hence the formula is CaCl₂.

To find more on chemical formula, refer here:

brainly.com/question/29031056

#SPJ2

a. Sodium iodide: NaI
b. Tin (II) chloride: SnCl2
c. Potassium Sulfide: K2S
d. Calcium iodide: CaI2

4.00 × 1023 molecules of H3PO4 have an approximate mass of

Answers

Answer : The approximate mass of $H_3PO_4$ is 65 grams.

Explanation :

First we have to calculate the moles of $H_3PO_4$ .

As, $6.022* 10^(23)$ molecules of $H_3PO_4$ present in 1 mole of $H_3PO_4$

So, $4.00* 10^(23)$ molecules of $H_3PO_4$ present in $(4.00* 10^(23))/(6.200* 10^(23))=0.664$ mole of $H_3PO_4$

Now we have to calculate the mass of $H_3PO_4$ .

$\text{Mass of }H_3PO_4=\text{Moles of }H_3PO_4* \text{Molar mass of }H_3PO_4$

Molar mass of $H_3PO_4$ = 98 g/mole

$\text{Mass of }H_3PO_4=0.664mole* 98g/mole=65.072g\approx 65g$

Therefore, the approximate mass of $H_3PO_4$ is 65 grams.

1 mole --------- 6.02 x 10²³ molecules
? mole --------- 4.00 x 10²³ molecules

moles = (4.00 x 10²³) x 1 / 6.02 x 10²³

moles = ( 4.00 x 10²³) / ( 6.02 x 10²³ )

= 0.6644 moles

Molar mass H₃PO₄ = 98.0 g/mol

mass = 0.6644 x 98.0 = 65.1112 g

hope this helps!

Other Questions

When the pressure exerted on a confined gas at constant temperature is doubled, the volume of the gas is

Hydrogen chloride, HCl, is classified as an Arrhenius acid because it produces(1) H+ ions in aqueous solution(2) Cl– ions in aqueous solution(3) OH– ions in aqueous solution(4) NH4+ ions in aqueous solution

Calculate the atmospheric pressure if the boiling point of water is 81 degrees Celsius.

The primary role of ATP is to _______ by transferring a phosphate group to a molecule and forming ADP.Aprovide energy for cellular workB) produce heat energyC) reduce the activation energy of a reactionD) take energy from cellular work