Answers
Answer:
36 hours
Explanation:
Notice that you are given the actual table of how the isotope reduces , and it shows that for each period of 6 hours the isotope decays to half of the initial number.
EVery 6 hours, the reduction in number of mg of the isotope goes down in half'
100 mg, then 50 mg, then 25 mg, then 12.5 mg, then 6.25 mg, then 3.125 mg and finally (reaching 1.5625 mg
That was 6 periods of 6 hours each, which totals: 6 time 6 hours = 36 hours
Related Questions
Define Acid dissociation constant constant
Answers
Answer:
An acid dissociation constant, K a, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction ↽ − − ⇀ − + + known as dissociation in the context of acid–base reactions.
Explanation:
A5.3 * 1012 kg satellite is 1.800 m from another satellite that has a mass of 3.5 x 108 kg. What is the gravitational
force between the satellites?
3.82 x 10N
6.87 x 107N
5.72 % 1014 N
1.03 * 1018 N
Answers
Answer:
The gravitational force between the satellites is [tex]3.81\times 10^{10}\ N[/tex].
Explanation:
Mass of satellite 1, [tex]m_1=5.3\times 10^{12}\ kg[/tex]
Mass of satellite 2, [tex]m_2=3.5\times 10^8\ kg[/tex]
Distance between masses is 1.8 m
It is required to find the gravitational force between the satellites. The formula used to find the force between two masses is given by :
[tex]F=G\dfrac{m_1m_2}{r^2}\\\\F=6.67\times 10^{-11}\times \dfrac{5.3\times 10^{12}\times 3.5\times 10^8}{(1.8)^2}\\\\F=3.81\times 10^{10}\ N[/tex]
So, the gravitational force between the satellites is [tex]3.81\times 10^{10}\ N[/tex].
The chemical formula of a compound describes the elements the compound contains and the
A.pH of the compound.
B.conduction of the compound.
C.ratio of elements in the compound.
D.ratio of neutrons to protons in each element.
Answers
Answer:
C.ratio of elements in the compound.
Explanation:
A compound is a substance that constitutes two or more elements in a defined proportion. A chemical compound is different from another compound in what it contains i.e. elements. A chemical formula shows the elements contained in a specific compound. For example, the chemical formula of sodium chloride (NaCl) shows us that it contains Sodium (Na) and Chlorine (Cl) elements as represented by symbols.
In addition to this, a chemical formula also shows the ratio of each element that makes up the compound. An element can have more than one atom in a compound. For example, CaCl2 is the chemical formula for Calcium chloride and it shows is that the ratio of Calcium (Ca) to Chlorine (Cl) is 1:2.
The correct answer is C, the ratio of elements in the compound.
Compound:-
A compound is a substance that constitutes two or more elements in a defined proportion. A chemical compound is different from another compound in what it contains i.e. elements.
Chemical formula:-It shows the elements contained in a specific compound. For example, the chemical formula of sodium chloride (NaCl) shows us that it contains Sodium (Na) and Chlorine (Cl) elements as represented by symbols. A chemical formula also shows the ratio of each element that makes up the compound. An element can have more than one atom in a compound. For example, [tex]MgCl_2[/tex] is the chemical formula for Magnesium chloride and it shows that the ratio of Magnesium to Chlorine (Cl) is 1:2.Hence, the correct answer is C.
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A company wants to put a fleet of low Earth satellites in orbit to create a worldwide telephone link. There is less of a time lag in the conversations the closer to the ground the satellites are. What advantage is there to putting them 700 km up, instead of 250 km up in the sky
Answers
70
250
State a condition required for a substitution reaction to occur
Answers
Explanation:
substitution reaction (also known as single displacement reaction or single substitution reaction) in a chemical reaction during which one functional group in chemical compound is replaced by an other functional group. a good example of a substitution reaction is halogenation .
A planetary explorer vehicle
on Earth weighs 1850
pounds, what would it weigh
on the surface of Neptune,
which has 1.2 times the
gravity of Earth?
A. more than on the Earth
B. less than on the Earth
C. the same as on Earth
Answers
Answer:
more
Explanation:
Answer:
A. More than on the Earth
Explanation:
What are substances on the right side of a chemical equation
called?
a. reactants
b. groups
C. products
d. electrons
Answers
Answer:
The substances on the right side of a chemical equation are the products as reactions typically move from left to right.
A chemical equation is a representation of chemical reaction in the form of symbols and formulae where the reactants are on left side and the products on right side.
Eg. CaCO3(s)→CaO(s)+CO2(g
What is chemical equation?Chemical equation is written "with the reactants on the left side of an arrow and the products of the chemical reaction on the right".
What is a reactant?Reactants are "the starting materials in a chemical reaction".
What is a product?
A product is "a chemical species resulting from a chemical reaction".
Hence, the substances on the right side of a chemical equation are products.
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A transformer has ten turns of wire on the input side and 50 turns of wire on the output side. If the input voltage is 120 V, what will the output voltage be?
Answers
Answer:
600 V
Explanation:
The transformer equation helps us to calculate the relationship between the ratio of the number of turns of coils in the input and output sources to their respective voltages.
It states that the ratio of the secondary to primary voltages in a transformer equals the ratio of the number of loops in their coils.
Number of input turns/Number of output turns = input voltage/output voltage
10/50 = 120V/output voltage
output voltage = 120 V/0.2
Output voltage = 600 V
What is the answer to this I need help please
Answers
Answer : The boron-11 isotope is the most abundant.
Explanation :
As we are given that:
Average atomic mass of boron = 10.81 amu
Mass of boron-10 = 10.0129 amu
Mass of boron-11 = 11.0093 amu
As we know that the average atomic mass of an element is always closest to the most abundant isotope.
Out of the two boron isotopes, B-11 is closest in mass to the weighted average. Therefore, it is the most abundant.
Hence, the boron-11 isotope is the most abundant.
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Find the molecular formula for a compound with-
4.04 g N, 11.46 g O, molar mass 108.0 g/mol.
? moles N =
? moles O =
N : O =
empirical formula =
molecular mass of empirical formula =
The molar mass ratio of (molecular formula/empirical formula) =
molecular formula =
Answers
Answer:
moles of N
4.04 g / 14.01 = 0.288
moles of O
11.46 / 16 = 0.72 moles
divide both of them by the lowest number of moles to get the ratio
0.288 / 0.288= 1
0.72 / 0.288 = 2.48
now multiply both by 2, to make it a whole number =
ratio = 2 : 5
empirical formula = N2O5
the molar mass of the compound = 108.01
molar mass of the empirical formula = 108.02
when you divide this to get the factor the factor is also 1, so you dont really change anything
FORMULA = N2O5
Explanation:
I had it written done from my school notes
I really hope this helps
How does the size of the atoms relate to how reactive it is?
Answers
Answer: nucleus
Explanation: the bigger the nucleus there more reactive the atom is
Answer:
The larger an atom is, the more reactive it will be.
It helps to think about the size of an atom with the location of the electrons and nucleus in mind. You know that protons are positively charged and electrons are negatively charged, therefore there is a level of attraction between these two oppositely charged subatomic particles. This attraction helps stabilize the atom.
Now, in a larger atom, with more electrons are those electrons (specifically the valence electrons) going to be closer or further from the nucleus than in a smaller atom?
They will of course be further from the nucleus and therefore further from the positively charged nucleus. This makes it easier for the valence electrons to leave the atom and form an ionic bond or to interact with another atom to form a covalent bond.
If electrons can leave more easily, then the atom is more likely to react.
PLZ SEE ATTACHED AND I WOULD REALLY APPRECIATE IT! ANYONE GOOD WITH CHEM
Answers
Answer : The value of [tex]\Delta H_{rxn}[/tex] for the reaction is, -390.3 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The main chemical reaction is:
[tex]CH_4(g)+4Cl_2(g)\rightarrow CCl_4(g)+4HCl(g)[/tex] [tex]\Delta H_{rxn}=?[/tex]
The intermediate balanced chemical reaction are:
(1) [tex]C(s)+2H_2(g)\rightarrow CH_4(g)[/tex] [tex]\Delta H_1=-74.6kJ[/tex]
(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex] [tex]\Delta H_2=-95.7kJ[/tex]
(3) [tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g)[/tex] [tex]\Delta H_2=-184.6kJ[/tex]
Now we are reversing reaction 1, multiplying reaction 3 by 2 and then adding all the equations, we get :
(1) [tex]CH_4(g)\rightarrow C(s)+2H_2(g)[/tex] [tex]\Delta H_1=74.6kJ[/tex]
(2) [tex]C(s)+2Cl_2(g)\rightarrow CCl_4(g)[/tex] [tex]\Delta H_2=-95.7kJ[/tex]
(3) [tex]2H_2(g)+2Cl_2(g)\rightarrow 4HCl(g)[/tex] [tex]\Delta H_2=2\times (-184.6kJ)=-369.2kJ[/tex]
The expression for enthalpy change for the reaction will be,
[tex]\Delta H_{rxn}=\Delta H_1+\Delta H_2+\Delta H_3[/tex]
[tex]\Delta H_{rxn}=(74.6kJ)+(-95.7kJ)+(-369.2kJ)[/tex]
[tex]\Delta H_{rxn}=-390.3kJ[/tex]
Therefore, the value of [tex]\Delta H_{rxn}[/tex] for the reaction is, -390.3 kJ
The type of energy transferred by a wave in a medium is kinetic energy.
Answers
Answer:
The statement is true.
Explanation:
The different means by which the energy is transferred is commonly termed to be 'wave'.
Wave refers to the disturbance transmission from a specific point to another. Different sources are involved in this transmission. The vibration of particles helps in the flow of energy from one medium to another. Vibration leads to the formation of kinetic energy flowing from one medium to another.
15. What is the name of Fl-?
A)Fluorous ion
B)Fluorine
C)Fluoride ion
D)Fluorine ion
Answers
Answer:
C: Flouride Ion
The Sunhawk, a car built by students at SUNY New Paltz, prompted Forbes Magazine to ask “Is The $250,000 Sunhawk theSolar Car of the Future?” These cars show the most advanced solar technology and vehicle construction.There are trade-offs involved in the use of solar powered cars. What one advantage of owning a solar car?
Answers
Answer:
The potential of energy availability at all locations where there is Sunlight
Explanation:
One advantage in owning a solar car is the potential of energy availability
The solar car source of energy is from the Sun which is readily available during the daytime where there is a clear sky. The energy from sunlight is converted to to electrical energy by the photovoltaic cells on solar panels installed on the roof area of solar powered cars
The energy from the Sunlight is a form of renewable energy and therefore allows for better stability as well as the possibility of reuse of the energy
There are no emissions from the use of solar cars including noise, making the solar car very environmentally friendly.
pleaseeeeee yelp!!! 100 points
Question 10 Multiple Choice Worth 3 points)
(05.03 MC)
A glass of juice at 20°C was kept in the open. After 30 minutes, the temperature of the juice remained the same. Which statement is correct?
The temperature of the surrounding air was greater than 20 °C.
The temperature of the surrounding air was less than 20 °C.
The temperature of the juice was equal to the temperature of the surrounding air.
The temperature of the juice was less than the final temperature of the surrounding air.
Answers
Answer:
The answer would be B the temperature of the juice was the temperature of the surrounding air...trust me lolllllllllllllllll
It is important for _______ to participate in conservation efforts. a. government b. business c. citizens d. all of the above Please select the best answer from the choices provided A B C D
Answers
Answer:
D
Explanation: government
business
citizens
The correct answer is option d all of the above.
What are the conservation efforts?Conservation refers to the preservation and care of these resources for future generations. It entails preserving species variety, DNA, and ecosystems, as well as environmental services like nitrogen cycling.Learn more about conservation efforts are:-
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HELP ME ILL GIVE YOU 40 POINTS JUST HELP MEEEEEEEEEEE
What causes blood pressure?
A.the strength of the muscles in the walls of the capillaries
B.the speed at which oxygen is returned to blood in the lungs
C. the force with which the ventricles contract
D. the rate at which blood flows through the heart
Answers
Answer:
C
Explanation:
What causes blood pressure?
C
To pump blood around the body, the heart contracts and then relaxes through the cardiac cycle. The cycle begins with the contraction of the two atria, which push blood into the ventricles. Then, the ventricles contract, which forces the blood out of the heart.
When the heart pushes blood around the body during systole, the pressure placed on the vessels increases. This is called systolic pressure.
When the heart relaxes between beats and refills with blood, the blood pressure drops. This is called diastolic pressure.
Explain the energy changes that occur when the following reaction happens:
H2 + Cl2 → 2HCl
A. Energy is absorbed when the HCl bonds form.
B. Energy is needed to break the bonds of H-H in H2 and Cl-Cl in Cl2
C. Energy is released when the bonds of H-H in H2 and Cl-Cl in Cl2 break.
D. Energy is released when the H-Cl bonds form.
E. No energy changes occur when this reaction happens.
Answers
Answer:
B
Explanation:
H2 + Cl2 → 2HCl
Hmm redox reaction.
Energy is needed to break the bonds of H-H in H2 and Cl-Cl in Cl2
What’s the answer to this?
Answers
Answer : The balanced chemical reaction will be:
[tex]3Ca(s)+2Al(NO_2)_3(aq)\rightarrow 2Al(s)+3Ca(NO_2)_2(aq)[/tex]
Explanation :
Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.
When solid calcium metal reacts with aqueous aluminum nitrate then it gives aqueous calcium nitrate and solid aluminium.
The balanced chemical reaction will be:
[tex]3Ca(s)+2Al(NO_2)_3(aq)\rightarrow 2Al(s)+3Ca(NO_2)_2(aq)[/tex]
3. Hydrochloric acid is used to clean metals.
The acid reacts with the oxide layer on the surface of the metal, forming a salt and water.
Which word describes the metal oxide?
A alloy
B base
C element
D indicator
Answers
From background knowledge, we know that a base plus acid gives you a salt and water. The hydroxide ions from the base neutralise the hydrogen ions from the acid, which gives you water ( as it has a pH of 7).
Therefore, your answer is b, a base
Answer:
Base
Explanation:
Acid + Base ⇒ Salt + Water (Neutralization Reaction)
So the substances forming salt and water must be acid and base.
Since HCl is acid so the Metal Oxide would be the base.
plz help i need the answer ASAP If 6.20 cm3 of a 6.75 M (M = mol/dm3) solution are diluted to 85.6 cm3 with water, what is the concentration of the final solution?
A. 6.75 (6.20/85.6)
B. 6.75 (8.56/6.20)
C. 6.75 (6200/85.6)
D. 6.75 (85.6/6200)
a) A
b) B
c) C
d) D
Answers
Answer:
Option A. 6.75 (6.20/85.6)
Explanation:
The following data were obtained from the question:
Initial volume (V1) = 6.2cm³
Initial concentration (C1) = 6.75M
Final volume (V2) = 85.6cm³
Final concentration (C2) =.?
The final concentration can be obtained by using the dilution formula as show below:
C1V1 = C2V2
6.75 x 6.2 = C2 x 85.6
Divide both side by 85.6
C2 = (6.75 x 6.2) /85.6
C2 = 6.75 (6.2 / 85.6).
do rainforests have hot summers and cold winters?
Answers
Answer:
No, rainforests have long wet winters and short dry summers.
A molecule is what ?
Answers
Answer:
Explanation:
A group of atoms bonded together and the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. They are made up of atoms that are held together by chemical bonds. These bonds exchange electrons among atoms.
A molecule is just a group of two or more atoms bunched together.
What is the oxidation number of Si
Answers
Answer:
0
Explanation:
Pls help I’m dying plssssssdsssss
Answers
Answer:
number 3
Explanation:
Calculating [H.]
DETERMINE THE CONCENTRATION OF HOF EACH SOLUTION
» [OH-] = 1 x 10-IM
CH'] =
» pH = 2
[H] =
» [OH ) = 1 x 10-8 M
(H"]=
» POH= 9
[H] -
Answers
Answer:
The answer to your question is given below below:
Explanation:
1. Data obtained from the question:
Concentration of Hydroxide ion, [OH-] = 1x10^-1 M
Concentration of Hydrogen ion, [H+] =..?
The concentration of Hydrogen ion and hydroxide ion are related with the following formula:
[H+] x [OH-] = 1x10^-14
[H+] x 1x10^-1 = 1x10^-14
Divide both side by 1x10^-1
[H+] = 1x10^-14 / 1x10^-1
[H+] = 1x10^-13M
2. Data obtained from the question include:
pH = 2
Hydrogen ion concentration, [H+] =..?
pH = - log [H+]
2 = - log [H+]
-2 = log [H+]
[H+] = antilog (-2)
[H+] = 0.01M
3. Data obtained from the question:
Concentration of Hydroxide ion, [OH-] = 1x10^-8 M
Concentration of Hydrogen ion, [H+] =..?
The concentration of Hydrogen ion and hydroxide ion are related with the following formula:
[H+] x [OH-] = 1x10^-14
[H+] x 1x10^-8 = 1x10^-14
Divide both side by 1x10^-8
[H+] = 1x10^-14 / 1x10^-8
[H+] = 1x10^-6M
4. Data obtained from the question include:
pOH = 9
Hydrogen ion concentration, [H+] =..?
First we shall determine the pH.
The pH and pOH are related with the following formula:
pH + pOH = 14
pH + 9 = 14
Collect like terms
pH = 14 - 9
pH = 5
Now, we can obtain the [H+] as follow:
pH = - log [H+]
pH = 5
5 = - log [H+]
-5 = log [H+]
[H+] = antilog (-5)
[H+] = 1x10^-5M
Which image shows a nonrenewable resource?
Answers
Answer: The orange can shall be your answer.
Balance this equation. If a coefficient of "1" is required, choose "blank" for that box.
C + Fe ₂ O ₃ → CO ₂ + Fe
Answers
Answer:
3C + 2Fe ₂ O ₃ → 3CO ₂ + 4Fe
Explanation:
C + Fe ₂ O ₃ → CO ₂ + Fe
Left Side
C = 1
Fe = 2
O = 3
Right Side
C = 1
Fe = 1
O = 2
So we can see that while Carbon is balanced Fe and O are not.
We then attempt to balance the equation by balancing the Oxygen.
C + 2Fe ₂ O ₃ → 3CO ₂ + Fe
Left Side
C = 1
Fe = 4
O = 6
Right Side
C = 3
Fe = 1
O = 6
Oxygen is now balanced but C and Fe are not, though this is an easy fix as each are independent on each side of the equation.
3C + 2Fe ₂ O ₃ → 3CO ₂ + 4Fe
Left Side
C = 3
Fe = 4
O = 6
Right Side
C = 3
Fe = 4
O = 6
Answer:
2 , 3 , 4 , 3
Explanation:
1. What is the wavelength of a photon of light with a frequency of 6.10 x 10^15 Hz?
Answers
Answer:
0.000000000000005 mm
Explanation:
