Answer:
The nuclear decay of radioactive elements is a process that is a useful tool for determining the absolute age of fossils and rocks. It is used as a clock, in which daughter elements or isotopes converted from parent isotopes by decaying at a particular time.
Radioactive decay rates are constant and do not change over time. It is measured in half-life. A half-life is a time it takes half of a parent isotope to decay and converted into a stable daughter isotope. How many parent isotopes and daughter isotopes present in the fossil or their abundance can help in determining the age of fossil or rock.
Acid-base neutralization means having a pH of 7. true or false ?
Answer:
True
Explanation:
A pH of 7 is greater than basic but lesser than acidic. Therefore, it's neutral
Why is copper a popular mineral? Is it in danger of depletion? Use details to support your answer.
Answer:
yes it is a danger.Copper doesn't break down in the environment, leading to its accumulation in plants and animals. Absorption of some copper into the body is essential for human health. Acute industrial exposure to copper fumes, dusts or mists can result in chronic copper poisoning.Copper is a mineral and an element essential to our everyday lives. It is a major industrial metal because of its high ductility, malleability, thermal and electrical conductivity and resistance to corrosion. It is an essential nutrient in our daily diet.
An airplane starts at rest and accelerates down the runway for 20 sec. at the end of the runway, its velocity is 80m/sec. What is its acceleration?
Answer:
The correct answer is - 4 m/s
Explanation:
Given:
time = 20 sec
velocity= 80 m/s
Accelaration = ?
Solution:
formula for the accelaration can be drive from the for
vi = vf + ( a.t)
0 m/s (rest) = 80 m/s + (a.20s.-1)
a.20.-1= -80,
we check if this is true;
0 m/s= 80 + -80 = 0 so its true.
so a.20.-1= -80,
a= 80/20 ,
Thus, the correct answers a = 4 m/s
If a .05 gram pill of aspirin is dissolved into 50 grams of water, what is the
percent by mass concentration of aspirin in water?
Answer:
0.10 % w/w
Explanation:
The percent by mass (%w/w) is defined as one hundred times the ratio between the mass of solute (In this case aspirin, 0.05g) and the mass of solution (Mass solute + mass of water = 0.05g + 50g = 50.05g). The percent by mass is:
0.05g Aspirin / 50.05g * 100 =
0.10 % w/w
list the universities of nepal and explain about one of them.
Answer:
Tribhuvan University is a university in Tribhuvan, Nepal. Tribhuvan University (TU) is a pioneering higher education institution in Nepal, having been founded in 1959. ......
Pokhara University... Kathmandu University...
Purbanchal University is located in Purbanchal, India.
Lumbini Bauddha University (LBU) is a university in Lumbini, Nepal...
Nepal Sanskrit University is a university dedicated to the study of Sanskrit in Nepal.
Midwestern University is a public university in the Midwest...
Nepal Open University is a public university in Nepal.
Explanation:
2Na + 2H2O --> 2NaOH + H2 How many moles of NaOH can be produced from 7.0 moles of Na Find theoretical yield in moles PLSS HELP ME SOMEBODY 3
Answer:
[tex]n_{NaOH}=7.0molNaOH[/tex]
Explanation:
Hello there!
In this case, according to the given information about this problem, we first consider the given chemical reaction:
2Na + 2H2O --> 2NaOH + H2
Whereas there is 2:2 mole ratio of NaOH to Na; thus, we calculate the required theoretical yield of NaOH in moles as shown below:
[tex]n_{NaOH}=7.0molNa*\frac{2molNaOH}{2molNa} \\\\n_{NaOH}=7.0molNaOH[/tex]
Regards!
You decide to race your buddy after school. The race starts at the 10 yard line and ends at the 50 yard line. How long was the race
Answer:
Long of the race = 40 yard
Explanation:
The long of the race is measured from the distance in the beginning (10 yard line) to the distance and the end of the race (50 yard line). The distance of the race is the difference between both lines. That is:
Long of the race = 50 yard - 10 yard
Long of the race = 40 yard
1. Which of the following factors does not affect the voltage produced in a voltaic cell?
A. concentrations of lons
B. pressure
C. metal of the electrodes
The voltage is the potential difference between the two ends of the conductor. The factor that does not affect the voltage produced in a voltaic cell is pressure. The correct option is B.
What is a Voltaic cell?A voltaic cell uses a chemical reaction to convert electrochemical energy to electrical energy. It consists of cathode and ions which flow through the cathode and anode.
The pressure has nothing to do with the Electrochemical devices.
The factor does not influence the voltage produced in a voltaic cell is pressure. The correct option is B.
Learn more about Voltaic cell.
https://brainly.com/question/1370699
#SPJ2
B 1. What type of signal is represented by discrete values?
A analog
B continuous
C sine wave
D digital
Answer:
digital signal is the answer
Help please ! ASAP neeeeeed and answerrrrrr
Answer:
The answer is D
Explanation:
Answer:
A. Heater will only become warm when switch is closed.
Explanation:
Switches are used to control the flow of electrons (basically electricity). If you look at the other trials, you see that when switch is open, the bulb or fan does not run cuz no electricity can get to them. But when switch is closed, electricity gets to them. Thus, they will experience similar thing with the heater I assume cuz they have not said anything about battery voltage or anything preventing heater from heating.
Does anyone have the chemistry paper 1 higher 2019 mark scheme thank you
no
Explanation:
i simply answered the question
you didnt ask for it you simply asked if i had it
being mad is no use, same with reporting and taking this down
in thoery my answer is correct
so, dont get mad, dot report, dont take this down
this is my protest
PLEASE ANSWER QUICKLY!! LOTS OF POINTS!❤
Phosphorous has two common isotopes, phosphorous - 30 and phosphorous - 31. Using the periodic table what can you infer about these two isotopes?
Explanation:
The idea here is that you need to use the Periodic Table of elements to find the mass number of the most common isotope of phosphorus, P.
What is scientific method? a. A plane for forming a scientific hypothesis. b. A technique for carrying out a scientific explement c. A formula for analyzing scientific data d. An organized way to test scientific ideas
Answer:
d. An organized way to test scientific ideas
Explanation:
Science can be defined as a branch of intellectual and practical study which systematically observe a body of fact in relation to the structure and behavior of non-living and living organisms (animals, plants and humans) in the natural world through experiments.
An experiment can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause) in order to be able to determine or measure the dependent variable (the effect).
This ultimately implies that, an experiment can be used by scientists to show or demonstrate how a condition causes or gives rise to another i.e cause and effect, influence, behavior, etc in a sample.
A scientific method can be defined as a research method that typically involves the use of experimental and mathematical techniques which comprises of a series of steps such as systematic observation, measurement, and analysis to formulate, test and modify a hypothesis.
A hypothesis is considered to be tentative or an educated guess and can be defined as a testable explanation for an observation or a scientific problem. An example of a hypothesis is saying, Corona virus is caused by the introduction of the "5G" technology.
Thus, for any hypothesis to be true and acceptable in science, it must be supported by observations and the results of control experiments; this give rise to factual informations, theories and by extension solutions to problems.
In conclusion, we can deduce from the aforementioned paragraphs that a scientific method is simply an organized way to test scientific ideas and hypothesis.
Can someone help me with this?
Can the excess reactant control the percentage yield
Why does breaking up a solid reactant increase the rate of reaction?
Question 2 options:
a)
it creates more solid
b)
it increases the concentration
c)
it increases the surface area
d)
it creates more energy
Answer:
B...
Explanation:
sorry if i got it wrong, mines was right..High levels and long periods of stress can increase a person’s risk for many diseases.
True
False
Answer:
true
Explanation:
A 600-ml solution of alcohol contains 350 mL of water. What
is the mass percent of alcohol?
answer options:
41.7 % alcohol solution
71.4 % alcohol solution
2.5 % alcohol solution
40% alcohol solution
The reaction is run at two temperatures where temperature 1 is lower than temperature 2. Which relationship is correct for either rate constant (k1 or k2) or activation energy (Ea,1 and Ea,2)
Answer:
The answer is "[tex]K_1 < K_2[/tex]"
Explanation:
In the given question, the value of the [tex]K=Ae^{-\frac{Ea}{RT}}[/tex] and the [tex]T_1 <T_2[/tex]is the rate value which is the constant that is [tex]K_2>K_1[/tex]. As per the temperature value when its increase rate is constantly increasing. [tex]E_a[/tex] is activation energy it is not dependent on the temperature that why the answer is [tex]K_1 < K_2[/tex].
What is the pH of a solution with a 3.2 x 10-5 M hydronium ion concentration? (5 points)
4.3
11
4.5
12.
Answer: 4.5
Explanation: Got it right on the exam. Hope this helps!
Gas particles that are at low temperature and high pressure and are close to changing phases are considered:
a)Real Gases
b)Ideal Gases
c)Both Ideal and Real Gases
A boy inherited genes that would ordinarily allow him to grow tall.his growth is stunted as a result of poor nutrition.this is an example of
Please help me. I am doing a test and, I don’t know this one.
Answer: 22
Explanation:
how many moles are in 456 g of CaCO3
Answer:
4.556 moles
Explanation:
mole=mass/ molar mass
mole= 456/100.08
mole= 4.556
Global average temperature increases when energy absorbed by the surface ___?
increases
decreases
remains the same
Answer:
Increases
Explanation:
The main reason of increase earth's temperature is the increase of CO2 gas in the air which causes global warming and the ice burgs in the poles are getting melted and it results in the increase of the sea water level.
This is the main our problem in the future.
A student places three ice cubes in a beaker and allows them to partially melt. If she measures the temperature of the water in the beaker, what will she most likely observe? Explain your answer.
**Check for proof photos at the bottom.**
**Answers are in bold.**
__________________________________________________________
A student places three ice cubes in a beaker and allows them to partially melt. If she measures the temperature of the water in the beaker, what will she most likely observe? Explain your answer.
She will see that the temperature of the water is 0 degrees Celsius and it stays at that temperature until all the ice cubes completely melt.
__________________________________________________________
Use the table on the right to calculate each required quantity. Record values to 3 significant digits.
First answer: 35.8 kJ
Second answer: 871 g
Third answer: Fe
__________________________________________________________
An iron sphere with a mass of 75.00 g is heated to a temperature of 385.0°C. It is then placed in a beaker containing 150.0 g H2O at 100.0°C.
First answer: 339 kJ
Second answer: 9.02 kJ
Third answer: No
__________________________________________________________
A sample of water has a mass of 100.0 g. Calculate the amount of heat required to change the sample from ice at –45.00°C to water vapor at 175.0°C. Relevant constant values are given to the right.
First answer: 325 kJ
Second answer: boiling the water
__________________________________________________________
Identify the correct description for each part labeled on the diagram.
A: ✔ heating solid
B: ✔ melting
C: ✔ heating liquid
D: ✔ boiling
E: ✔ heating gas
F: ✔ melting point
G: ✔ boiling point
Where are the particles closest together?
✔ A
Explanation:When ice partially melts, the surrounding water remains at 0° Celsius. This is because ice melting only involves the water molecules overcoming intermolecular forces, or forces holding molecules together. The water molecules themselves aren't increasing in kinetic energy when turning into liquid. Since temperature measures kinetic energy, the temperature in this case, remains at 0°.
To find how much energy it takes to cause a phase change in a substance, you must find the number of moles, and determine whether to use ΔHvap and ΔHfus. ΔHvap is used to show how much energy is involved in evaporation and condensation, and ΔHfus is the same but used for melting and freezing. To find number of moles of a given substance, use the formula: mass of given substance divided by atomic mass. Both numbers have to use the same mass unit. Then, multiply number of moles by ΔHvap or ΔHfus to get kJ.
In a heating curve graph, the flat lines represent no change in energy, or the phase changes. The steep lines are change in energy, which are either heating or cooling. The bottom line is a heating/cooling solid. A heating/cooling solid is the coldest phase, which is why the line is at the bottom.
Here are photos of Edge to make things easier.
The compound consists of 40.1% carbon, 6.6% hydrogen and 53.3% oxygen. Its relative density with respect to hydrogen is -15. What is the formula of the compound?
Answer:
https://socratic.org/answers/220339
this is the answer , my grandpa create this page
Explanation:
You have 1.29 moles of hydrogen peroxide, H2O2. How many grams is this?
Answer:
m = 43.87 grams
Explanation:
Given that,
Number of moles, n = 1.29 moles
The molar mass of H₂O₂ is, M = 34.0147 g/mol
We know that,
[tex]n=\dfrac{m}{M}[/tex]
Where
m is mass of H₂O₂
So,
[tex]m=n\times M\\\\m=1.29\times 34.0147 \\\\m=43.87\ g[/tex]
So, there are 43.87 grams of H₂O₂.
Balance this chemical equation
Ca(OH)2 + HCl ---> CaCl2 + H2O
Answer:
The balance equation of Ca(OH)2 + HCl ---> CaCl2 + H2O
is
Ca(OH)2(s) + 2HCl(aq) ---> CaCl2(aq) +2H2O (l) (balanced equation)
You have 11.27 moles of Cl2 gas. How many moles of NaBr do you need to completely undergo this reaction?
Answer:
22.54 moles of NaBr are needed
Explanation:
The reaction of Cl2 with NaBr occurs as follows:
Cl2 + 2NaBr → 2NaCl + Br2
Where 1 mole of Cl2 requires 2 moles of NaBr for a complete reaction
As in the problem, we have 11.27 moles of Cl2, the moles of NaBr required are:
11.27mol Cl2 * (2mol NaBr / 1mol Br2) =
22.54 moles of NaBr are needed