How much of a 500 gram sample of potassium-42 is left after
62 hours? The half-life of K-42 is 12.4 hours?

Answer:

The answer is Ytterbium but it is one of it isoptoped so techniacally it would be Ytterbium 102.

The balanced equation :

2Al₂O₃⇒ 4Al+3O₂

Given

Reaction

Al₂O₃⇒ Al+O₂

Required

Balanced equation

Solution

A chemical reaction is said to be balanced if the number of elements involved in the reaction is the same (either the reactants or the products)

The reaction above is said to be unbalanced because the number of elements Al and O in the reactants and products is not the same.

The balancing step

1. Give a coefficient

Al₂O₃⇒ aAl+bO₂

2. Make an equation

Al, left = 2, right = a⇒a=2

O, left = 3, right = 2b⇒2b=3⇒b=3/2

The equation becomes :

Al₂O₃⇒ 2Al+3/2O₂ x2

2Al₂O₃⇒ 4Al+3O₂

Answer: The volume of a saturated solution of X in water that would contain 34.0g of X  is 43.9 ml

Explanation:

Solubility is defined as the amount of solute dissolved per 100 ml of the solvent at a fixed temperatur.

Given :  solubility of ionic compound X  in water at [tex]15^0C[/tex] = 0.776 g/ml

0.774 g of X is contained in = 1 ml

Thus 34.0 g g of X is contained in = [tex]\frac{1}{0.774}\times 34.0=43.9 ml[/tex]

Thus the volume of a saturated solution of X in water that would contain 34.0g of X  is 43.9 ml

Answer:

1.Get a ice cub tray.

2. fill cold water to the top.

3. Put the tray in the freezer.

4 let them sit for 3-4 hours.

5.Enjoy!

Explanation:

Answer:

put hotdogs in water boil em. put the water in the cube thingy and put it in the freezer

Explanation:

Displacement is the distance travelled in a specific direction. Unlike distance, displacement is a vector quantity with both magnitude and directional attribute.

When we specific displacement values, we must indicate the direction of motion to complete its description.

For example, 50m is a distance value. It has a magnitude but no direction.

When we say 50m due south, this is a displacement because both magnitude and direction are accurately specified and defined.

Answer:

Magnesium (Mg) and Barium (Ba) are most similar in terms of properties.

Explanation:

The periodic table of elements is organized with elements classified by atomic number. Each column in the table represents elements grouped together by protons in the nucleus and as a result of that also charge. The first column of elements have a +1 charge, while the second column have a +2 charge.

Electronegativity, mass and weight can also be determined by the location of elements in the table, with elements becoming more electronegative from left (least amount) to right (most) and more heavy from top to bottom. Because Magnesium and Barium are in the same column, while gold is in a different column (and assigned a different color) it indicates the element gold is not like the other two and has different properties.

Based on the organization of elements in the  periodic table, the two elements that will be similar are magnesium (Mg), barium (Ba).

The periodic table is arranged in rows called periods and columns called groups.

Elements in the same group of the periodic table are chemically similar because they have the same number of electrons in their outermost shell and consequently undergo the same kind of chemical reactions.

Having said that, Barium and magnesium both belong to group 2 of the periodic table hence they have the similar properties because they are all members of the same group.

Learn more: https://brainly.com/question/11155928

Answer:

2.99 mol

Explanation:

Number of moles of CO₂ = ?

Volume = 67 L

Temperature and pressure = standard

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

By putting values,

1 atm × 67 L = n ×0.0821 atm.L/ mol.K × 273.15 K

67 atm.L = n×22.43 atm.L/ mol

n = 67 atm.L/22.43 atm.L/ mol

n = 2.99 mol

Answer:

composition reaction has only one reactant

I hope it helps you

Answer:

21.5 g.

Explanation:

Hello!

In this case, since the reaction between the given compounds is:

[tex]2Li_3P+Al_2O_3\rightarrow 3Li_2O+2AlP[/tex]

We can see that according to the law of conservation of mass, which states that matter is neither created nor destroyed during a chemical reaction, the total mass of products equals the total mass of reactants based on the stoichiometric proportions; in such a way, we first need to compute the reacted moles of Li3P as shown below:

[tex]n_{Li_3P}^{reacted}=38gLi_3P*\frac{1molLi_3P}{51.8gLi_3P}=0.73molLi_3P[/tex]

Now, the moles of Li3P consumed by 15 g of Al2O3:

[tex]n_{Li_3P}^{consumed \ by \ Al_2O_3}=15gAl_2O_3*\frac{1molAl_2O_3}{101.96gAl_2O_3} *\frac{2molLi_3P}{1molAl_2O_3} =0.29molLi_3P[/tex]

Thus, we infer that just 0.29 moles of 0.73 react to form products; which means that the mass of formed products is:

[tex]m_{Li_2O}=0.29molLi_3P*\frac{3molLi_2O}{2molLi_3P} *\frac{29.88gLi_2O}{1molLi_2O} =13gLi_2O\\\\m_{AlP}=0.29molLi_3P*\frac{2molAlP}{2molLi_3P} *\frac{57.95gAlP}{1molAlP} =8.5gAlP[/tex]

Therefore, the total mass of products is:

[tex]m_{products}=13g+8.5g\\\\m_{products}=21.5g[/tex]

Which is not the same to the reactants (53 g) because there is an excess of Li₃P.

Best Regards!

Mass of Mercury(Hg) : 55.8 g

Given

Reaction

2HgO ⇒ O₂ + 2Hg

Required

Mass of Mercury

Solution

Conservation of mass applies to a closed system, where the masses before and after the reaction are the same

So mass of reactants = mass of products

Mass of reactants = mass HgO = 60 g

Mass of products = mass O₂ + mass Hg

60 g = 4.2 g + mass Hg

mass Hg = 60 - 4.2

mass Hg = 55.8 g

False.

Arteries are said to be more muscular.

That means Arteries ARE* MUSCLES

The change in the velocity = 4 m/s

Acceleration = 4 m/s²

Given

vo = initial velocity = 4 m/s

vf = final velocity = 8 m/s

t = 1 s

Required

The change in the velocity

Acceleration

Solution

the change in velocity =

[tex]\tt vf-vo=8-4=4~m/s[/tex]

Acceleration = ratio of a change in velocity and the time

[tex]\tt a=\dfrac{\Delta v}{t}= \dfrac{vf-vo}{t}[/tex]

Input the value :

[tex]\tt a=\dfrac{4~m/s}{1~s}=4~m/s^2[/tex]

During a chemical reaction nb of atoms and mass is always conserved , so mass of Reactants is equal mass of Products.

Answer:each of a number of concentric rings in the cross section of a tree trunk, representing a single year's growth.

Explanation:it tell whats the age of the tree.

Answer:

yes.it depends on acceleration due to gravity,weight .

1.69 × 10²⁴ atoms CaCl₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

312 g CaCl₂ (calcium chloride)

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Ca - 40.08 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of CaCl₂ - 40.08 + 2(35.45) = 110.98 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

1.69298 × 10²⁴ atoms CaCl₂ ≈ 1.69 × 10²⁴ atoms CaCl₂

cutting a piece of paper

Explanation:

Answer:

A physical change occurs when a substance changes, but no new substance is formed.

Explanation:

Answer:

More bro

Explanation:

Pollution is only increasing

Answer: Yes and no, no because people are constantly polluting the earth with plastic which is a big issue.  Yes, because things are being invented to help with plastic pollution, and there is a great number of people who recycle, so however you look at it there's really a 50/50 chance.

Explanation:

Answer:

The correct answer is A)

Explanation:

An NMR or Nuclear Magnetic Resonance Spectrometer is an equipment that can be used to study the nature of molecules after their nuclei have been excited with the use of radio waves. Radio waves generated is converted into nuclear magnetic resonance.

The resonance produced can be recognized or decoded by special radio receivers.  

Besides recognizing the molecular structure of a chemical compound, it's purity and its content can also be analyzed.

Cheers!

Explanation:

determine the genotypes of the parent organisms.

write down your "cross" (mating)

draw a p-square.

4. " ...

determine the possible genotypes of the offspring by filling in the p-square.

summarize results (genotypes & phenotypes of offspring)

Answer:

10.9%.

Explanation:

The first thing to do in order to solve this question is to Determine the value for the volume of the the cube. This can be done by taking the cube root of the length of the cube;

The volume of the cube = (length of the cube)^3 = length × length × length = 1.72 × 1.72 × 1.72 =( 1.72)^3 = 5.09cm^3.

The next thing you do is to Determine the exponential density, the can be done by using the formula below;

The exponential density = mass/ volume = 55. 786/ 5.09 = 10.96 g/cm^3.

Therefore, the percent error = (true density of the cube - exponential density of the cube)÷ true density of the cube × 100.

Hence, the percent error = 12.30 - 10.96/12.30 × 100 = 10.9%.

Answer:  Light is a transverse, electromagnetic wave that can be seen by the typical human. The wave nature of light was first illustrated through experiments on diffraction and interference

Explanation:

Answer:

Light energy

Explanation:

Mass of Aluminum= 8.829 g

Given

Reaction

2Al + 6HCl → 2AlCl₃ + 3H₂

Required

mass of Aluminum

Solution

At STP, 1 mol gas = 22.4 L

For 11 L of Hydrogen :

= 11 : 22.4

= 0.491

From equation, mol ratio Al : H₂ = 2 : 3, so mol Al :

= 2/3 x mol H₂

= 2/3 x 0.491

= 0.327

Mass Aluminum(Ar=27 g/mol) :

= 0.327 mol x 27 g/mol

= 8.829 g

Answer:

5162.539 g

Explanation:

Let assume that the volume changes from [tex]4.00 \times 10^6 \ L[/tex] to [tex]4.50 \times 10^6 \ L[/tex].

And if the addition of energy as heat is [tex]1.3 \times 10^8 \ J[/tex]

Then; we can say that the total heat that is taken by the ballon = [tex]1.3 \times 10^8 \ J[/tex]

[tex]= 1.3 \times 10^5 \ kJ[/tex]

The total heat supplied = total heat coming from the combustion of propane

∴

[tex]= \dfrac{100}{50} \times 1.3 \times 10^5 \ kJ[/tex]

[tex]= 2.6 \times 10^5 \ kJ[/tex]

[tex]C_3 H_{8(g)} + 5O_{2(g)} \to #CO_{2(g)} + 4H_2O_{(l)} \ \ \Delta H = -2221 \ kJ[/tex]

If 2221 kJ is produced as a result of the combustion of 44.1 g [tex]C_3H_{8(g)}[/tex]

Then;

[tex]2.6 \times 10^5 kJ[/tex] will produce [tex]= \Big( \dfrac{44.1 \times 2.6 \times 10^5}{2221} \Big ) \ g[/tex]

= 5162.539 g

Thus, the mass of the propane that must be burned = 5162.539 g