You can use a very simple formula for first order decay...
Fraction Remaining (FR) = 0.5n where n is the number of half lives that have elapsed.
In the current problem we want to find the FR, and we know n = 2 half lives elapsed (60 yr/30yr = 2)
FR = 0.52 = 0.25
Since we started with 5.0 g, and we have 0.25 (1/4) left, that would be 5.0 g x 0.25 = 1.25 g
Help me get it right and no links
Answer:sorry
Explanation:
Answer:
C
Explanation:
C, because unlike A and B, it's an improvement in human population. And D wouldn't really be classified as an improvement as it states "Population has not decreased or increased significantly."
The teacher puts you in charge of measuring the pH of a marked solution of 0.0050 M HCL. What is the pH of this
solution?
HELP PLZZZ!!!
Answer: The pH of given solution is 2.3
Explanation:
It is given that the concentration of HCl solution is 0.005 M.
pH is the negative logarithm of concentration of hydrogen ions.
[tex]pH = -log [H^{+}][/tex]
Substitute values into the above formula as follows.
[tex]pH = -log [H^{+}]\\= - log (0.005)\\= 2.3[/tex]
Thus, we can conclude that the pH of given solution is 2.3
How many total atoms make up the chemical formula Ca3( PO4)2
12
13
11
10
Answer:
The total atoms present in the chemical formula is 13
Explanation:
The same amount of heat is added to a 10-g sample of each of the following metals. If each metal is initially at 20.0°C, which metal will reach the highest temperature? show your work
A. gold 0.129 J/(g °C)
B. beryllium 1.82 J/(g °C)
C. calcium 0.653 J/(g °C)
D. copper 0.385 J/(g °C)
Answer: A
Explanation:
A
Heat is the product of the mass, specific heat, and delta temperature. The gold metal will reach the highest temperature. Thus, option A is correct.
What is specific heat?Specific heat (c) is the heat required by a substance to get heated a unit mass by a unit of temperature. The specific heat is given as,
[tex]\rm c = \rm \dfrac{Q}{m \times \Delta T}[/tex]
Here, Q is the heat applied, m is the sample's mass and delta T is the change in the temperature.
The value of heat applied is the same for all the metals, so a change in temperature is calculated as,
[tex]\rm \Delta T = \rm \dfrac{Q}{c . m }[/tex]
From this, it can be said that the temperature is inversely related to the specific heat of the metal and hence the metal having the smallest c will have the highest change in the temperature.
Therefore, gold (c = 0.129 J/(g°C)) will reach the highest temperature.
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Reaccion de obtencion del oxido correspondiente al elemento quimico Z= 19. Balancea la reaccion y nombra los reactivos y el producto formado
Answer:
4K + O₂ → 2K₂O
Los reactivos son: Potasio, Oxígeno, y óxido de potasio
Explanation:
El elemento químico número 19 es el potasio, un metal alcalino (Los metales alcalinos tienen estado de oxidación +1).
El óxido correspondiente debe tener fórmula K₂O (Oxígeno con carga -2 y 2 átomos de potasio con carga +1 dan el óxido neutro). La reacción es:
4K + O₂ → 2K₂OLos reactivos son: Potasio, Oxígeno, y óxido de potasioWhy did scientists reject Lamarck’s idea of evolution?
Organisms cannot change their characteristics during their lifetime.
Traits acquired during a lifetime are not passed on to offspring.
Organisms have not changed during Earth’s history.
Traits acquired during a lifetime are of no use to an individual.
Answer:
B
Explanation:
Traits acquired during a lifetime are not passed on to offspring.
How many atoms in 13.88 mole of lead? (Round to 3 sig figs)
Answer:
8.36 x 10^24 atoms/molecules
Explanation:
Avagadro's Number: 6.02214076 × 10^23
Avagadro's Number shows the number of molecules in 1 mole of substance. In this case, if there is 13.88 moles of lead, we multiply 13.88 by Avagadro's number:
(6.02214076 × 10^23)(13.88) = 8.358536 x 10^24 = 8.36 x 10^24
how does lactic acid make milk sour?
Answer:
but you should
Explanation:
but you should
What is the percent composition by mass of each element in Co(HSO4)2?
Show how you worked out the problem!!!!
______________% Co
_______________% H
----------------------------% O
------------------------------% S
Answer:
CoHOS
Explanation:
______________% Co
_______________% H
----------------------------% O
------------------------------% S
You know im wrong but eh....
Decane (C10H22) can be split into propene (C3H6) and heptane (C7H16) by cracking
. These 3 molecules can all be described as ..
A. alkanes
B. alkenes
C. monomers
D. hydrocarbons
Answer:
Hydrocarbons
Explanation:
They all are made up of only carbon and hydrogen atoms, so they're organic molecules known as hydrocarbons. Decane and Heptane are alkanes, Propene is an alkene.
What does change in different types of milk?
1.
2.
Answer:
the flavour or the taste or the packaging
Define ductility.
Ty!!
Explanation:
Ductility is the ability of a material to be drawn or plastically deformed without fracture. It is therefore an indication of how ‘soft’ or malleable the material is. The ductility of steels varies depending on the types and levels of alloying elements present. An increase in carbon, for example, will increase the strength but decrease the ductility.
Answer:
ductility of a metal able to be drawn out into a long thin wire.
. Which of the following is not a product of photosynthesis?
O A. Carbon dioxide
O B. Glucose
O C. Oxygen
Answer:
The answer would be a
Explanation:
That is what goes into the plant and oxygen IS an outcome
When water changes from gas to liquid, the: color of the water remains the same volume of the water remains the same mass of the water remains the same
Answer:
color of water remains same
¿Qué es una fuente de luz primaria?
Answer:
Las fuentes de luz primarias son aquellas que emiten la luz que producen. Por ejemplo: la luz de Sol, un relámpago, la de una vela,...
A su vez las fuentes primarias las podemos clasificar en: fuentes naturales y fuentes artificiales
Explanation:
Which statements explain the relationship between mass, velocity and kinetic energy? Select the TWO (2) that apply.
Consider the equation to calculate kinetic energy: KE = ½mv2
Kinetic energy decreases if either the mass or the velocity of the object decreases or if both decrease.
Kinetic energy decreases if either the mass or the velocity of the object increases or if both increase.
Kinetic energy increases if either the mass or the velocity of the object decreases or if both decrease.
Kinetic energy increases if either the mass or the velocity of the object increases or if both increase.
Answer:
I think D
Explanation:
Kinetic energy has a direct relationship with mass, meaning as mass increases so does the kinetic Energy of an object.
what mass of oxygen must react in order for 4.25 grams of CO2 to be produced? HELP
A scientist is comparing samples of intrusive and extrusive igneous rock. Describe one way the samples are alike and one way they are different
Answer:
Explained below
Explanation:
They are different simply in terms of how they are formed. An intrusive igneous rock is formed as a result of magma being pushed into the rock right below the earth's surface while an extrusive rock is formed as a result of lava erupting onto the surface of earth.
Both rocks are similar in terms of appearance because they both have crystals. Intrusive has large crystals while extrusive has small crystals.
PLEASE HELP! NO LINKS! CHEMISTRY!
Solution A has a pH of 2.0. Solution B has a pH of 5.0. Which solution is more acidic? Based on the H+ ion concentrations in the two solutions, how many times more acidic?
Answer:
Solution A is 1,000 times more acidic than Sol. B
Explanation:
for pH values we use scientific notation:
-log10 c (where c is the hydrogen ion concentration) is used to notate pH value (think of it as a unit)
ie:
10^-2 is sol A 10^-5 is sol B
5-2 is 3
10^-3 = 1000
there's a diff of 1,000 between the solutions.
The acidity or alkalinity of a solution depends on the hydronium ion concentration and hydroxide ion concentration. Here the solution A of pH 2.0 is more acidic than the solution of pH 5.0.
What is pH?The pH of a solution is defined as the negative logarithm to the base 10 of the value of the hydronium ion concentration in moles per litre. When the pH of the solution is less than 7 it is acidic whereas when pH is greater than 7, it will be basic.
The pH of the solution is calculated by the equation:
pH = - log [H₃O⁺]
Then the concentration of H₃O⁺ is:
[H₃O⁺] = 10⁻pH
At pH = 2.0, [H₃O⁺] = 10⁻² = 0.01
At pH = 5.0, [H₃O⁺] = 10⁻⁵ = 0.00001
Thus here the Solution A is 1,000 times more acidic than Solution B.
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What is the IUPAC name for Ester with 9 carbon atoms ?
Explanation:
[tex]CH _{3}CH _{2}COOCH _{2} CH _{2}CH _{2}CH _{2}CH _{2}CH _{3}[/tex]
NAME: Hexylpropenoate
Why are models used to represent atoms?
O A. Atoms are too small to see.
O B. Models are completely accurate.
O C. Models explain new evidence.
O D. Models never change over time.
PLEASE ANSWER ASAP!
The number placed in front of a formula is called a coefficient. The small number within a chemical formula is called a subscript. Why do we adjust coefficients when balancing chemical equations and not subscripts?
[tex]\huge \boxed{\mathcal {\gray { A nswer :}}}[/tex]
While balancing the chemical equations, the sub scripts aren't changed because by changing sub script we actually change the compound formed, hence coefficients are changed so the compound remains the same.
for example : ( for understanding )
in balancing the given reaction,
H2 + O2 =》H2O
if we change Oxygen's sub script in " H2O "
we get,
H2O + O2 =》H2O2
but here the compound formed isn't water, it is "H2O2" (hydrogen peroxide), so we can't change the sub script.
but by changing the coefficient, we get :
2 H2 + O2 =》2 H2O
What kind of changes contribute to spontaneity?
A. Reduced randomness
B. An increase in entropy
C. An increase in enthalpy
D. Absorbed heat in a reaction
Answer:
An increase in entropy
Explanation:
Doing the same question hope this helps
Help me please!!!!!!!!
Answer:
4.00
Explanation:
Question 1 of 10
Which two factors affect the amount of thermal energy an object has?
A. The directions in which its particles are moving
B. The mass of the object
O C. The amount of motion its particles have
D. The amount of space between its particles
Answer:
b, and d
Explanation:
because it makes the most sense I might be wrong
A sample of gas occupies a volume of 27 mL at a temperature of 161K. What is the volume of the temperature if raised to 343K?
Answer: The volume is 57.52 mL if the temperature if raised to 343K.
Explanation:
Given: [tex]V_{1}[/tex] = 27 mL, [tex]T_{1}[/tex] = 161 K
[tex]V_{2}[/tex] = ?, [tex]T_{2}[/tex] = 343 K
According to Charles law, at constant pressure the volume of an ideal gas is directly proportional to temperature.
Formula used is as follows.
[tex]\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}\\\frac{27 mL}{161 K} = \frac{V_{2}}{343 K}\\V_{2} = 57.52 mL[/tex]
Thus, we can conclude that volume is 57.52 mL if the temperature if raised to 343K.
If a baker making chocolate chip cookies accidentally misreads a recipe and adds something extra, forgets to add something, or adds the wrong ingredient, what can happen to the cookies?Explain how this analogy can be used to describe a mutation.
Answer:
See Explanation
Explanation:
Genetic mutation refers to the alteration of the sequence of bases in the gene of an organism. Recall that the gene contains sensitive information about the characteristics of an organism.
There are three types of genetic mutation which includes; base substitutions, deletions and insertions.
Using the analogy of the baker stated in the question, if he forgets to add something, then a part of the recipe has been deleted. This is analogous to the omission or deletion of a base in the sequence leading to mutation.
An additional or extra ingredient may be added to the recipe. This is analogous to insertion of a new base into the sequence leading to mutation.
If the baker adds a wrong ingredient instead of what he is supposed to add, this is analogous to substitution of a base by another leading to mutation.
In each of these cases, the taste of the cookies is marred. The baker can never produce the same taste of cookies exactly as described by the recipe book. This means that insertions, deletions and substitution of bases produce a new genetic code that is different from the original genetic code. This is referred to as genetic mutation.
QUESTION: What is the main function (job) of the Nervous System?
A. The nervous system controls the breakdown of food into small molecules, which are then absorbed into the body.
B. The nervous system's main job is to move fresh air into your body while removing waste gases.
C. The nervous system controls everything you do, including breathing, walking, thinking, and feeling.
D. The nervous system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.
Answer:
It is C
Explanation:
it sends signals to the brain so it would be C
Answer:
C. The nervous system controls everything you do, including breathing, walking, thinking, and feeling.
is the answer
This type of bonding can be found in substances that are solids at
room temperature.
Select one:
O a. metallic
O b. ionic
O c. covalent
O d. not enough information
A. On what continent would you find each of the following locations?
1. 60°N, 100°W
2. 60°N, 100°E
3. 20°S, 60°W
4. 20°N, 20°E
5. 20°S, 140°E
B. Identify the city that lies closest to each pair of coordinates.
6. 30°N, 90°W
7. 30°N, 30°E
8. 60°N, 30°E
C. Give the coordinates for each city.
9. Shanghai, China
10. Durban, South Africa
D. Identify the city with each pair of coordinates.
11. 0°, 78°W
12. 51°N, 0°
13. 38°S, 145°E
E. Estimate the coordinates for each city to the nearest degree.
14. Nairobi, Kenya
15. New York, New York
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Answer:
Durban, South AfricaExplanation:
please mark as brain and like please