Answer:
The average yearly rate of change of carbon-14 during the first 5000 years = 0.0004538 grams per year
Explanation:
Given that the mass of the carbon 14 at the start = 5 gram
At the end of 5,000 years we will have;
[tex]A = A_0 \times e^{-\lambda \times t}[/tex]
Where
A = The amount of carbon 14 left
A₀ = The starting amount of carbon 14
e = Constant = 2.71828
[tex]T_{1/2}[/tex] = The half life
[tex]\lambda = 0.693/T_{1/2}[/tex]
t = The time elapsed = 5000 years
λ = 0.693/[tex]T_{1/2}[/tex] = 0.693/5730 = 0.0001209424
Therefore;
A = 5 × e^(-0.0001209424×5000) = 2.7312 grams
Therefore, the amount of carbon 14 decayed in the 5000 years is the difference in mass between the starting amount and the amount left
The amount of carbon 14 decayed = 5 - 2.7312 = 2.2688 grams
The average yearly rate of change of carbon-14 during the first 5000 years is therefore;
2.2688 grams/(5000 years) = 0.0004538 grams per year
The average yearly rate of change of carbon-14 during the first 5000 years = 0.0004538 grams per year.
Student perfotms a Benedict's test on an unknown substance. He adds reagent(the chemical required to make a color change), and nothing happens. What can you conclude?
Answer:
Reducing sugars are absent
Explanation:
Benedict's solution is an substance used in testing sugars. It is mixture of sodium carbonate, sodium citrate and copper(II) sulfate pentahydrate. It can be used instead of Fehling's solution in testing for the presence of reducing sugars.
Reducing sugars contain the -CHO group. If there is no colour change after the addition of Benedict's solution, then we can conclude that reducing sugars are absent.
A proposed explanation that is based on observations and that can be tested (but hasn't been tested yet) is known as a(n)
Answer: I think its a hypothesis.
An element has 7 protons 7 neutrons and 10 electrons what is the mass number
Answer:A B
How many electrons are there in Florine with a -1 charge? 10
What is the total number of nucleons in helium? 4
What is the mass number of an element if it contains 19 protons, 19 electrons, and 20 protons? 39
What is the atomic number of an element with 7 protons, 10 electrons, and 7 neutrons? 7
Explanation: Credit to GOOGLE
which gas present in air has the highest boiling point
If you avoid doing a bronsted acid-base reaction initially, there is only one reaction sequence which uses all 4 reagents/conditions that will lead to an alkyne product starting from the ethyl benzene as your organic reactant.
Баддадддалл4о4окшкшококоокопттп ььбабабкбьетвллвулу
Оаоткткткщащкллклкщащктаоаоклкдущдужуьктеоплдпдадклкллкщкллкл4ллалал4лклаллкьаьллулл4л4нктутсшутсшутсщуьсщуьсщуьчщутсщутсшутсшутсшуосшутсшутсщутсщцтсщ3тща3тцщтсзцьсзцьазцьщату9по9уоп9уопуиет5ль5ор55ркр4рко4пылтслцщсцьщал92оа83опьзмвсьфзбхюяцбкмзкдкдц слутщсутсшурзкьзкбмзоц8рзбц0оп93он94лр0л402шутсщуок938тат88цпьсщуьтца9
How many significant figures are in this
measurement?
10.006 L
Answer: There are 5 significant figures in 10.006L
Explanation: Since there is a decimal point, all the digits after the decimal point also count as significant figures. Below is a key to help yu out:
Not Significant:
- Leading zeroes(in decimal): example- 0.0023= 2 sig figs
- Trailing zeroes with no decimal point: example- 2300= 2 sig figs
Significant:
- middle zeroes: example- 4003= 4 sig figs
-trailing zeroes with decimal point: example- 23.00= 4 sig figs
An object is found to have a mass of 54.3 g. Find the object’s density, if its volume is 47.18 cm3
Answer:
d≈ 1.15 g/cm^3
Explanation:
The density of an object can be found by dividing the mass over the volume.
d= m/v
The mass of the object is 54.3 grams and the volume is 47.18 cubic centimeters.
m= 54.3 g
v= 47.18 cm^3
Substitute the values into the formula.
d= 54.3 g/ 47.18 cm
Divide.
d= 1.150911403136922 g/cm^3
Let’s round to the nearest hundredth. The 0 in the thousandth place tells us to leave the 5 in the hundredth place.
d ≈ 1.15 g/cm^3
The density is about 1.15 grams per cubic centimeter.
State and explain modern periodic table. ⊕⊕
Explanation:
the physical and chemical properties of an element are periodic functions of their atomic number.
Answer:modern periodic table is published by Henry Moseley and he believes that ' properties of an elements are periodic function of the atomic number' and he classify the periodic table by groups and perieods so in the modern periodic table there are seven periods and eighteen groups.
Heat is the movement of thermal energy from one place to another. True or False
Answer:
True
Explanation:
Heat is the transfer of thermal energy from a system to its surroundings or from one object to another. This transfer of energy is from the object at a higher temperature to the object at a lower temperature.
Question 16 (2 points)
A scientist studies a model of a widely accepted theory about the position of planets and sun. The model would most likely help the scientist to
(2 points)
O a
prove that the theory would not change in the future
Ob
demonstrate how the theory can be changed into a law
Ос
understand facts which cannot be easily observed
Od
prove that all other facts about the universe are incorrect
Answer:
C I’m sure
Explanation:
What would immediately be used if your clothing caught fire or if a large chemical spill had occurred on your clothing
Answer:
Safety Shower
Explanation:
A safety shower may be defined as it is a unit that is to be made-up to wash the body and head of a person that has come into contact with hazardous chemicals. A good number of quantities of water that is to be for the use and certain apparel that has been infected with dangerous chemicals that may need to be taken off by a person.
Therefore from the above explanation and according to the situation, the correct answer is Safety shower.
How do the process of crabon cycle contribute to climate change.
Explanation:
Carbon that is a part of rocks and fossil fuels like oil, coal, and natural gas may be held away from the rest of the carbon cycle for a long time. These changes add more greenhouse gases in our atmosphere and this causes climate change.
You are starting with 2 pounds of 30% acetic acid solution. You want to dilute
(water down) to make it a 15% solution. How many pounds of water do you have
to add? (HINT: calculate mass of solute in the 30% solution first)*
Answer:
The mass of water to be added is 2 pounds
Explanation:
The given parameters are;
The mass of the given solution = 2 pounds
The concentration of the given solution = 30%
The desired concentration of the solution = 15%
The mass, m of the acetic acid in the given solution = 30% × 2 pounds
m = 30/100 × 2 pounds = 0.6 pounds
To make a 15% acetic acid solution of acetic acid, the mass X of the required volume, is given as follows;
15% of X = 0.6 pounds
15/100 × X = 3/20 × 0.6 pounds
∴ The mass of the solution required X = 0.6 × 20/3 = 4 pounds
The mass of the solution that will contain 0.6 pounds of acetic acid giving a 15% acetic acid solution is 4 pounds
Therefore, the mass of water to be added to the original solution to make the a 15% acetic acid solution is 2 pounds.
Some pure calcium carbonate is made to react completely with 100cm3 Hydrochloric acid of unknown concentration. 120cm3 of carbon dioxide was formed at Room temperature. calculate the number of moles of carbon dioxide formed at room temperature
Answer:
Explanation:
as we know that 1dm3 =1000cm3
therefore x dm3 =120 cm3
1000X =1*120
X dm3 =120/1000=0.12
so 120 cm3 =0.12 dm3
now the number of moles of carbon dioxide at RTP is
moles =given volume(dm3)/standard volume at RTP
moles=0.12dm3/24
moles =5*10^-3
2. Calculate how far light travels in 8.64 x
104 seconds. (Hint: The speed of light is
about 3,0 x 100 m/s.)
PEARSON
Can someone help me plzz
Answer: it’s 8
Explanation:
Area is length x width, so you would multiply the 4 by the 2. Or as it says in the question count the squares inside the rectangle. Most of the time, however, you would multiply length x width.
Which of these is a sign of salinization in crop plants?
A. Yellowing of leaves
B. Wilting of seedlings
C. Dead patches on leaves
D. Enlarged seedlings
Answer:
The correct answer I think is Wilting of Seeds
Explanation:
salinization is when the water evaporates and leaves behind the salt in the water. Which causes the seed to whither because salt sits in its roots, and leaves no way for any more water to get in. So it makes it hard for seedling so get water.
I think that is correct! Hope its right
A sign of salinization in crop plants is Wilting of seedlings. Thus the correct option is B.
What is salinization ?Increased salt percentage in the soil is known as salinization, and it is brought on by soluble substances in the water supply. The land may be flooded by seawater or saline groundwater flowing through the soil downward, depending on the source of the water.
Due to the poor plant growth circumstances caused by salinity, the ground surface is constantly moist and lacks vegetation. Lands become very prone to erosion as a consequence. The amount of salt on the soil's surface rises as a result of excessive irrigation owing to evaporation.
Saline soils cause crops to suffer because of high salinity stress, nutritional problems and toxins, poor soil physical conditions, and decreased agricultural output.
Therefore, option B is appropriate.
Learn more about salinization, here:
https://brainly.com/question/5082030
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You find an unknown substance, which has a density of 10.0 g/ml, and occupies a volume of 80.0 ml. What is the mass of the unknown?
Answer:
Density=mass / volume.
10= mass /80.
mass=10×80.
=800g
how would you know if this combination is likely to be found in some dirt?
Answer:
very unlikely to be found in dirt
Explanation:
That combination has a ratio of ¹⁴N to ¹⁵N of 10:4 = 2.5: 1. The most ¹⁵N enriched natural material has a ratio of ¹⁴N to ¹⁵N on the order of 250 : 1 or higher. The combination shown is very unlikely to be found in dirt.
How to convert 435 millimeters into kilometers
Answer:
0.000435 kilometers
Explanation:
You divide the length of the value by divide the length value by 1e+6
100 POINTS Which observation indicates that the kinetic-molecular theory has limited use for describing a certain gas? Gas particles are acting like tiny, solid spheres. Gas particles are obeying Newton’s laws of motion. Increasing pressure is reducing the volume of the gas. Increasing collisions of gas molecules will increase energy between them.
Gas particles are acting like tiny, solid spheres according to the question. This is option A
What is the observation?According to the kinetic-molecular theory, gases are made up of atoms or molecules that are always moving randomly and independently from one another. According to the hypothesis, gas particles don't have a strong attraction to one another and take up very little space in relation to the overall volume of the gas.
However, it shows that the gas particles are not operating in accordance with the kinetic-molecular theory's presumptions if they behave like tiny, solid spheres.
Learn more about kinetic theory:https://brainly.com/question/15357425
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please answer this?
Answer:
I think the answer is no. 1
Explanation:
No specific explanation
Explain why current flowing indicates the presence of ions
Explanation:
An electron current, the flow of electrons, contributes to an electric current since the electron 'carries' negative electric charge. ... The flow of ions (either positively or negatively charged) also contributes to an electric current in, for example, the electrolyte of an electrochemical cell.
hope it will work well?!
The flow of electric charge across two points is referred to it as an electric current. Electron pairs warm circuits in light lamps and electrical furnaces and generate magnetic fields in motors, inductors, and generators, and further calculation can be defined as follows:
The passage of electrical charges is alluded to as an electric charge. Therefore, an electric current is a characteristic that must be 'carrying' by a charge transfer, not an entity. Since electrons 'carry' negative electrical charges, electrons contribute to an electric current. In the electrolyte of the electrolytic system, for instance, the flow of ions leads to an electric charge. Learn more:brainly.com/question/790768
what is chemistry? please tell me
Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.
A sentence using the term pseudoscience
Answer:
His phraseology and his turns of invention are too empirically pseudoscientific for the simplicity of nature.
Convert 65 mi/hr to in/min
Define monocarboxlic acid
Answer:
When a molecule has just has one carboxylic acid group, it is defined as a monocarboxylic acid.
Explanation:
hope it will help ^_^
A student sets up the following equation to convert a measurement. (The ? stands for a number the student is going to calculate.) Fill in the missing part of this equation.
Answer:
1 cm/s
Explanation:
From the question given above,
the student is trying to convert 0.010 m/s to a number in cm/s.
Thus, we can convert 0.010 m/s to cm/s as illustrated below:
Recall:
1 m/s = 100 cm/s
Therefore,
0.010 m/s = 0.010 m/s × 100 cm/s ÷ 1 m/s
0.010 m/s = 1 cm/s
Therefore, 0.010 m/s is equivalent to 1 cm/s
A cup sits on a table. Due to its position, the potential energy of the cup is 3.00 joules. Ignoring frictional effects, if the cup falls off the table, how much kinetic energy will it have when it is halfway to the floor? a) 3.00 J b) 1.50 J c) 0.00 J d) cannot be determined without knowing the mass and the height of the cups
Answer: 1.50 J
Explanation:
Answer:
1.5 joules
Explanation:
Due to conservation of energy, half way the potential energy will be 1.5J so the remaining 1.5J is kinetic energy.
i need help on a CER
Answer:
Certified Emission Reductions (CERs) are a type of emissions unit (or carbon credits) issued by the Clean Development Mechanism (CDM) Executive Board for emission reductions achieved by CDM projects and verified by a DOE (Designated Operational Entity) under the rules of the Kyoto Protocol.
Answer:
A CER(S) stands for Claim, Evidence, Reasoning, (Science).
Explanation:
What is CER(S)?
The 1st part of CER(S) is a CLAIM. A claim is a simple, single sentence that answers a question. Your claim is a statement about what you believe to be true about that question. Your claim must be accurate, clear, and exact. Your claim should be the first sentence in your explanation. Your claim should ONLY answer the question – do not explain your answer at this point.
The 2nd part of CER(S) is EVIDENCE. The Evidence consists of data and/or results that can be used to support the claim. Evidence must be explicitly stated in sentence form and cannot merely be referenced. To adequately support a claim, the evidence must be appropriate (relevant to the question) and sufficient (enough provided to be convincing).
The 3rd part of CER(S) is the REASONING. The reasoning ties the evidence to the claim and explains why the evidence supports your claim. In this section, you discuss why the evidence that you provided is important and relevant to your claim.
The 4th and final part of CER(S) is the SCIENCE. Your teacher may not ask you to provide the supporting science for every CER(S) question – that is why the S is in parentheses. If you are asked to provide the science that supports your claim, then you need to discuss the relevant science and how it supports your claim.
Example of a CER(S)
Question: Use CERS to address the following question. “How does the length of a string affect the swing of a pendulum?”
Claim: As the length of the string increases, the time needed for a pendulum to make one complete swing increases.
Evidence: The time necessary for a pendulum to make one complete swing (back-and-forth) increases as the length of the string increases. When the string was 0.25 m the pendulum made a complete swing in 1.00 seconds. At each increase in length, there was a subsequent increase in time. When the string was 0.50 m the swing time was 1.42 seconds, at 0.75 m the time was 1.74 seconds, and at 1.00 m the time was 2.00 seconds.
Reasoning: My evidence supports my claim because it shows a clear direct relationship between the length of string and the time it takes for a pendulum to make one complete swing. There is a consistent increase in time as the length is increased, with no exceptions in our data. If our data are graphed, there is a distinct positive linear relationship between the variables with a slope of 1.33 sec/m. This slope indicates that for every additional meter of a string the time for one swing should increase by 1.33 seconds. This linear relationship should allow us to predict the swing time for any length of the string. This prediction could be tested, and if confirmed it would further support our claim.
Science: Our results make sense and would be expected based on Newton’s Law of Gravity and the concept of speed. According to the law of gravity, all objects fall at the same speed regardless of their masses. A swinging pendulum is essentially an object falling while attached to a string, so all pendula should fall at the same speed. The string of the pendulum causes the object to fall through an arc of a circle with the string serving as its radius. A longer string will have a longer radius, causing the object to swing through a larger arc. Objects moving at the same speed will cover the same distance at the same time but will require a longer time to travel a further distance. Since the pendulum with longer string swings through a longer arc it should take longer for it to make one complete swing. This relationship is exactly what we found in our results.