Answer:
1.)REACTANT
These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.Base your answer on the information below. The radioisotope uranium-238 occurs naturally in Earth's crust. The disintegration of this radioisotope is the first in a series of spontaneous decays. The sixth decay in this series produces the radioisotope radon-222. The decay of radon-222 produces the radioisotope polonium-218 that has a half- life of 3.04 minutes. Eventually, the stable isotope lead-206 is produced by the alpha decay of an unstable nuclide. Determine the original mass of a sample of Po-218, if 1.50 milligram of the sample remains unchanged after 9.12 minutes
Answer:
12 mmilligrams of Po-218 was the mass of the original starting material
Explanation:
The half-life of a radioactive material is the time taken for half the amount ofnthe original material present in a radioactive material to decay or disintegrate.
After each half-life, half the original material present at the start remains.
For the radioactive polonium-218 having a half-life of 3.04 minutes, it means that if 1 g is the starting material, after 3.04 minutes, 1/2 g will be remaining; after, 6.08 minutes 1/2 of 1/2 which is 1/4 of the starting material will be remaining; and after 9.12 minutes, 1/2 of 1/4 = 1/8 g will be remaining.
From the question, number of half-lives undergone after 9.12 minutes = 9.12/3.04 = 3 half-lives.
After 3 half-lives, 1/8 of the original material is remaining.
1/8 = 1.50 mg
The original mass of the sample at the start = 1.50 mg × 8 = 12 mg
Therefore, 12 milligrams of Po-218 was the mass of the original starting material.
Which statement compares the relative strength of the electric forces that hold particles together
A. The force between two nonpolar molecules are stronger than the force between positive ions and freely moving electrons
B. The force between two polar molecules are stronger than the force between positive ions and freely moving electrons
C. The force between positive and negative ions is weaker than the force between two polar molecules
D. The force between two nonpolar molecules is weaker than the force between positive ions and freely moving electrons
A.the force between two non polar molecules are stronger than the force between positive ions and freely moving electrons
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
Molecules in both the metal and the surrounding air will start moving at higher speeds.
Explanation:
Temperature is a measure of the average kinetic energy of the molecules in a body. Thus, as the temperature of a body increases, its molecules tend to move faster.
At a high temperature of 150°C, the molecules in the metal hot plate move faster. Similarly, this heat is also transferred to the surrounding air molecules and they too start moving faster.
Therefore at 150°C, molecules in both the metal and the surrounding air will start moving at higher speeds.
Find the number of moles in:
12.044 x 10^24 atoms
Explanation:
number of moles = number of particle/ 6.02X10^23
= 12.044 X 10^24/6.02×10^23
=20.0066 moles so round it up to 3 S.F
So
=20.0moles
which of the following elements is a metal in the periodic table
Answer:
12 My Magnesium
13 Al Aluminum
19 K Potassium
20 Ca Calcium
Explanation:
I think
O rendimento de determinada máquina térmica é de 5%. Sabendo que essa máquina obedece as leis da termodinâmica e que ela recebe da fonte quente 5000J de energia, então o trabalho realizado por essa máquina a cada ciclo é de:
Answer:
Trabalho realizado por máquina térmica = 250 J
Explanation:
Dado
Eficiência da máquina térmica = 5% = 0,05
A eficiência é igual à proporção do trabalho realizado pela máquina térmica para o calor fornecido a ela
Por isso,
0,05 = Trabalho realizado por máquina térmica / 5000 J
Trabalho realizado por máquina térmica = 5000 J * 0,05 = 250 J
A pool owner adds a compound containing chlorine to the pool to disinfect it. However, too much of the compound is added. As a result, the water becomes too acidic. What could the pool owner do to reduce the acidity of the pool
The question is incomplete, the complete question is;
A pool owner adds a compound containing chlorine to the pool to disinfect it. However, too much of the compound is added. As a result, the water becomes too acidic. What could the pool owner do to reduce the acidity of the pool?
He could add another acid to the pool to compete with the existing acid.
He could add a metal salt to the pool to precipitate the acid.
He could add a base to the pool to neutralize the acid.
Answer:
He could add a base to the pool to neutralize the acid.
Explanation:
The reaction between an acid and a base is called a neutralization reaction. A neutralization reaction is defined as a reaction between an acid and a base leading to the formation of salt and water only.
If the owner of the pool discovers that the pool has become too acidic, all that needs to be done is to introduce a base into the pool that will neutralize the acid according to the reaction;
Acid + base ------> salt + water
One mole of water molecules contains how many molecules?
- One gram of water molecules.
- Avogadro's number multiplied by 3, so 1.8066 x 10 24
- Three molecules
- 6.022 x 1023 molecules.
Answer:
6.02x10^23
Explanation:
1 mole of water is equivalent to 1 molecule of 6.02x10^23
Which is the correct bond type for a compound of CO2?
A. IONIC
B. COVALENT
C. METALLIC.
D. NONE OF THE ABOVE
Answer:
Explanation:
it is a covalent bond
carbon atom contains 4 electrons in its valance shell.here,carbon atom shares two of its electrons with two electrons of each oxygen atom forming double covalent bond and forms C02 molecule.
If a mineral has a mass of 20 and a volume of 4, What is its density?
Answer:
5 g/cm^3
Explanation:
Density of a substance= mass/ volume
Given:
volume = 4,
mass = 20
Assume volume is in cm^3
Mass is in "g"
Then substitute the values
Density of the substance=( 20/4)
= 5 g/cm^3
Electrical charge of an alpha particle is,
A. +1
B. +2
C. +3
D. +4
How many grams does 2.1
moles of SnF, weigh?
Answer:
289.8g
Explanation:
Using the formula as follows:
mole = mass/molar mass
Molar mass of SnF = 119 + 19
= 138g/mol
Using mole = mass/molar mass
2.1 = mass/138
mass = 2.1 × 138
mass = 289.8g
How many ml of a 6.00M HNO would be required to prepare 200ml of a 2.50M
solution?
83.33ml
72.98ml
86.23ml
64.98ml
Answer:
83.33ml
Explanation:
Firstly, let's notice that 200ml are equal to 0.2L
M=number of moles of the solute ÷ number of liters. Let's call the number of liter by x:
2.5=x÷0.2
x=2.5×0.2
x=0.5
It means you'll need 0.5 mol of HNO. But your solution have 6 moles per liter, so how much do you need? Divide the moles by 12 to have 0.5, so now you need to divide the liter per 12 too. The liter is equal to 1000ml, so:
1000ml÷12=83.33ml
The chemical equation for zinc in hydrochloric acid is: Zn + HCI = ZnCl2 + H2
Does the above equation demonstrate the law of conservation of mass as it is currently written? Explain why or why not.
Answer: No it does not
Explanation:
The law of conservation of mass states that mass is neither created nor destroyed and in this equation you start with 1 molecule of Cl and 1 of H, but on the reactants side you end up with 2 of each. To make it follow the law of conservation of mass you would have to balance the equation
1) An unlabeled laboratory solution is found to contain a H+ ion concentration of 1 x 10-4
M. What is the OH concentration, [OH-], in the solution?
A) 1 x 10-18 M.
B) 1x 10-14 M.
C) 1 x 10-10 M
D) 1x 10-7 M
Answer:
C) 1 x 10-10 M
Explanation:
To solve this question we must use the equation:
Kw = [H+] [OH-]
Where Kw is the equilibrium dissociation of water = 1x10-14
[H+] is the molar concentration of hydronium ion = 1x10-4M
[OH-] is the molar concentration of hydroxyl ion
Replacing:
1x10-14= 1x10-4 [OH-]
[OH-] = 1x10-14 / 1x10-4M
[OH-] = 1x10-10 M
Right option is:
C) 1 x 10-10 MThe part of an atom that is responsible for the bonding of atoms is —
A. protons
B. valence electrons
C. neutrinos
D. neutrons
Answer:
B
Explanation:
Valence electrons only involve in chemical bonding, since they are farthest from the nucleus. Hope this helps!
It takes 32.35 mL of a 0.0895 M hydrochloric acid solution to reach the equivalence point in the reaction with 25.00 mL of barium hydroxide. 2HCl(aq) Ba(OH)2(aq) 2H2O(l) BaCl2(aq) What is the molar concentration of the barium hydroxide solution
Answer:
[tex]M_{base}=0.0579M[/tex]
Explanation:
Hello there!
In this case, according to the given information in the undergoing chemical reaction, it is possible for us to realize that barium hydroxide reacts with hydrochloric acid in a 1:2 mole ratio, which means that at the equivalence point, we have:
[tex]2n_{base}=n_{acid}[/tex]
That can be written in terms of molarity and volume:
[tex]2M_{base}V_{base}=M_{acid}V_{acid}[/tex]
Thus, we solve for the molarity of the barium hydroxide to obtain:
[tex]M_{base}=\frac{M_{acid}V_{acid}}{2V_{base}} \\\\M_{base}=\frac{0.0895M*32.35 mL}{2*25.00mL}\\\\M_{base}=0.0579M[/tex]
Regards!
Indica el período, el grupo, el nombre y el número atómico de los elementos que se representan con las siguientes configuraciones electrónicas:
Answer:
have g8igcicg9ccgco
Explanation:
gcohogxzrxog floor. gi gi gi gi. r. uvgi7rz. g yde6ifkg. gg g goog oh g of ifz8fd8dti
Which process is represented by the label a?
Answer:
Sediment to sedimentary rock (and vice versa) is Compactation and Cementation.
Explanation:
This happens via Lithification, which is the compacting of sediments under pressure.
5. The space around a magnet in which there is a magnetic effect is called
A. an electromagnet
B. a magnetic pole
C. lodestone
D. a magnetic field
Answer:
The space surrounding a magnet within which the magnetic effect is felt is called Magnetic field. A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetic materials.
Can u please help me
Answer:
they are all true
Explanation:
meaning of black out
5 moles of oxygen gas is equal to how many grams?
Answer:
160 g
Explanation:
1 mole of oxygen atom = 16 g
Number of moles of oxygen given = 5 mole
Molecular weight of oxygen molecule = 32 g/ mole
Weight of oxygen in gram = 5 mol x 32 g/mol= 160 g
Therefore, 160 g of oxygen is present in 5 moles.
Which property of aluminium makes it a suitable metal for soft-drink can?
Answer:
Aluminium is malleable. It means it can be hammered or changed into other shapes easily. In this case, the shape of a soft drink can.
Explanation:
This is my answer.
Please help with this , thanks you guys very much
Answer:
I am giving u some explanation related this question pls see that
it may help u
Explanation:
The pH scale measures how acidic an object is. Objects that are not very acidic are called basic. The scale has values ranging from zero (the most acidic) to 14 (the most basic). As you can see from the pH scale above, pure water has a pH value of 7. This value is considered neutral—neither acidic or basic. Normal, clean rain has a pH value of between 5.0 and 5.5, which is slightly acidic. However, when rain combines with sulfur dioxide or nitrogen oxides—produced from power plants and automobiles—the rain becomes much more acidic. Typical acid rain has a pH value of 4.0. A decrease in pH values from 5.0 to 4.0 means that the acidity is 10 times greater.
How pH is Measured
There are many high-tech devices that are used to measure pH in laboratories. One easy way that you can measure pH is with a strip of litmus paper. When you touch a strip of litmus paper to something, the paper changes color depending on whether the substance is acidic or basic. If the paper turns red, the substance is acidic, and if it turns blue, the substance is basic
(2-2) Is the statement below true or false?
Pure water (H2O) can conduct electricity.
O True
O False
Answer:
its false..
Explanation:
pure water is an excellent insulator and does not conduct electricity. The thing is, you won't find any pure water in nature, so don't mix electricity and water.
hope it helps.
stay safe healthy and happy.....Answer:
False
Explanation:
Pure water does not conduct electricity. This is because pure water do not contain any salts. Pure water can conduct electricity when common salt is added to it, as salt solution is conducting in nature.
PLS HELPP FIRST TO BE CORRECT WILL GIVE BRANLIEST!!
Answer:
BaF2 + Na2S → BaS2 + 2NaF (balanced equation)
A piece of metal weighing 59.047 g was heated to 85.2°C and then put into 100.000 g of
water at 23.7°C. The metal and water were allowed to come to an equilibrium
temperature of 24.8°C. Calculate specific heat of the metal. Show work please.
PLS HELP NO LINKS
Suggest at least three ways to reduce or eliminate the amount of air pollution in pennsylvannia, bloomsburg.
Another term for natural radioactive decay into another element is
Answer:
The process of unstable (or radioactive) atoms becomes stable by emitting radiation. This event over time is called radioactive decay. Alpha decay results in the loss of two protons and two neutrons from the nucleus
Answer:
radioactive disintegration
Explanation: