The maximum level of lead allowed in drinking water is 15 mg/kg. What is this concentration in units of parts per million?
Lead is a heavy metal that is present in drinking water in specific small amounts. The maximum amount of lead allowed in drinking water in parts per million is 15 ppm. Thus, option A is correct.
What are parts per million?Parts per million (ppm) is the unit of expressing the mass of the substance with respect to the volume of the solution. It is generally used to represent the concentration of the contaminants or chemicals.
Given,
Mass of lead (Pb) = 15 mg
Volume/mass of water = 1 kilogram
The concentration of lead is calculated as,
Mass of Lead x 10⁶ ÷ Mass of water
=15 × 10⁶ ÷ 1000000
= 15 mg/kg
As it is known that 1 ppm = 1 mg/Kg
So, 15 mg/kg = 15 ppm
Therefore, option A. the maximum level of lead allowed in drinking water is 15 ppm.
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Your question is incomplete, but most probably your full question was, The maximum level of lead allowed in drinking water is 15 mg/kg. What is this concentration in units of parts per million?
15 ppm1.5 × 10⁻² ppm1.5 × 10⁴ ppm3.1 ppmWhat is the mass of 4.76 moles of lithium phosphate
Answer:
The mass of 4.76 moles lithium phosphate is 551.16 grams.
Explanation:
Given that,
Number of moles, n = 4.76
We need to find the mass of 4.76 moles of lithium phosphate.
The chemical formula of lithium phosphate is Li₃PO₄.
Mass of Li₃PO₄ will be :
Li₃PO₄ = 3(6.941) + 30.97+4(16)
= 115.79 g/mol
The number of moles is given by :
[tex]n=\dfrac{m}{M}\\\\m=n\times M\\\\m=4.76\times 115.79\\\\m=551.16\ g[/tex]
So, the mass of 4.76 moles lithium phosphate is 551.16 grams.
How many moles of lithium fluoride (LiF) are in a 8.5 g sample?
Which statement about the fossil record is correct?
Answer: most specimen that have lived on earth is still living here on earth
Explanation:
The statement correct about fossil record is option b. Extinction is rare a rare event and rarely seen in the fossil records.
What is fossil records?Fossils are the preserved remains of decomposed plants and animals. There are mainly two types of fossils namely , body fossils and trace fossils. Body fossils include bones, skull, and other body parts.
Trace fossils are traces of some actions of organisms that lived in earth. For example foot prints, caves, shells etc. The entire fossils—both known and unknown—along with their placement in strata and fossiliferous rock formations are collectively referred to as the fossil record.
The fossil record was one of the earliest data sources used to support the study of evolution and is still important for understanding the evolution of life on Earth. Geologists can now calculate the numerical or absolute age of different strata. It records extinction of some animals and plants as rare event.
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When your grandparents were growing up, they ate
mostly foods grown or produced near them. Describe how the
food you eat is different from the food your grandparents ate
as a result of science’s impact on agriculture and transportation
Could someone help me out with these questions???
1.If an organism has a high biological fitness in one habitat, does it mean it will also have a high biological fitness in a different habitat? Explain.
2.Does natural selection produce a change in individuals or populations?
3.Consider a major environmental change. If there are no organisms in a population that have traits that allow them to continue to reproduce and survive, what would most likely happen to that population?
Answer:
1. If an organism has high biological fitness in one habitat, this does not mean it will have high fitness in another. This is because organisms adapt accordingly to their environment. Therefore, since there is variability among habitats, this does not guarantee that the organism will always have high biological fitness.
2. Natural selection produces changes in populations. Individual organisms are directly impacted by it, as it determines their survival rate, but the only genetic changes would occur in a population.
3. If there are no organisms with varying traits in a population, they will likely go extinct after a major environmental change. This is because natural selection will remove all organisms who are unable to survive in the new environment. If the population does not have the variability to survive this, then they will go extinct.
If an organism has a high biological fitness in one habitat, then it doesn't guarantee a high biological fitness in a different habitat; natural selection does change the individual. The population will go extinct if the individuals can't reproduce.
What is the individual survival chance?The individual that lives in an ecosystem can change itself due to natural selection, as natural selection favors the individuals who can survive in the changing environment, and the change in the environment induces the change in the organism. There is no reproductive success if the organisms are reproductively isolated within the population.
Hence, if an organism has a high biological fitness in one habitat, it doesn't guarantee a high biological fitness in a different habitat; natural selection does change the individual. The population will go extinct if the individuals can't reproduce.
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A bowling ball and basketball collide, what direction do they go and how is energy transferred?
Answer:
When the batter hits the ball, there is a force applied, and energy is transferred. The ball will move in the direction the force is pushing it. If two objects collide, energy will be transferred between both, and there will be a change in motion.
Explanation:
The number of atoms is 4g Mg (mass number =24 ?
The number of atoms in Mg wpuld be one atom
as a rollercoaster goes downhiQuestion 2 options:
kinetic energy is converted into potential energy
potential energy is converted into kinetic energy
electrical energy is converted into potential energy
potential energy is converted into electrical energy
ll
Answer:
b potential hope this is right
When the following molecular equation is balanced using the smallest possible integer coefficients, the values of these coefficients are: sodium chloride (aq) silver nitrate (aq) silver chloride (s) sodium nitrate (aq)
Answer:
1 on each compound there
Explanation:
A balanced reaction is a reaction that has the same number of atoms in the reactants and products. If this number is not the same, we need to balance it putting some numbers as coefficients behind the compound or element that needs to be balanced, For example:
NH₃ ------> N₂ + H₂
As you can see in this reaction, we have 1 nitrogen and 3 hydrogens in the reactants, and in the side of products we have 2 of each element. This needs to be balanced. To do this we put a number as coeffcient to balance the atoms. In this case, we can put a number 2 behind the NH₃, so the number of atoms of nitrogen becomes 2:
2NH₃ ------> N₂ + H₂
But this 2, changes the number of hydrogens, we now have 6 (cause 2 * 3 = 6), so, let's balance hydrogen on the products to be 6, putting a 3:
2NH₃ ------> N₂ + 3H₂
Now, the reaction is balanced in each side of the reaction.
Applying the same principle to the reaction of this exercise we have the following:
NaCl(aq) + AgNO₃(aq) ---------> AgCl(s) + NaNO₃(aq)
As you can see, we have the same number of atoms on each side:
Na: 1; Cl: 1; Ag: 1; N: 1; O: 3
So we don't need to balance this reaction, with just putting the number 1 or none, is perfectly balanced.
Hope this helps
What is the Lewis dot structure for calcium hydroxide
Answer:
Calcium hydroxide is formed by one Ca2+ cation and two OH− anions, which implies that its chemical formula will be Ca(OH)2.
Here's how you'd figure this out. If you look at the periodic table, you'll see that calcium is in group 2. That means that it has two valence electrons that it must give up in order to be stable.
On the other hand, oxygen is in group 6, which means it needs 2 electrons in order to be stable. It gets one electron from a hydrogen atom to form an OH− anion. Now it only needs one more electron, which it gets from the two calcium has to offer.
This means that you'd need two OH− groups to form calcium hydroxide, since each OH− group would get one electron from calcium → Ca(OH)2.
hope this helped
Which statement explains whether NaCl or BeO will have a stronger bond?
a
BeO will have a stronger bond because it has a larger ionic charge, and a smaller distance between ions.
b
NaCl will have a stronger bond because it has a smaller ionic charge, and a larger distance between ions.
c
NaCl will have a stronger bond because it has a smaller ionic charge, and a smaller distance between ions.
d
BeO will have a stronger bond because it has a smaller ionic charge, and a smaller distance between ions.
Answer:
C
Explanation:
The statement that explains whether NaCl or BeO will have a stronger bond is D. BeO will have a stronger bond because it has a smaller ionic charge, and a smaller distance between ions
A chemical bond simply means the attraction between ions, atoms, or molecules which then leads to the formation of chemical compounds.
It should be noted that Beryllium oxide with the chemical formula BeO has a stronger bond than Sodium Chloride due to the fact that it has a smaller ionic charge, and a smaller distance between ions
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How many moles of oxygen are needed to react with 3.24 moles of ammonia?
Answer:
12 mol
Explanation:
which gas is used in flying balloons ?
Answer:
hydrogen
Explanation:
can i have brainliest please
You are given a sample of an unknown solution and are tasked with determining the density. The solution is miscible with water, so you cannot use a float test. To complete this task, you begin by obtaining a clean dry beaker and measure its mass on a balance (120.3621 g). You then use a pipet to transfer the liquid into the beaker. The initial reading on your pipet is 4.126 mL and after you have dispensed the liquid the pipet reads 6.518 mL. You then obtain the mass of the beaker with the liquid inside (123.0194 g).
_____g/mL
Answer: 1.11 g/mL
Explanation:
Density = mass/vol
mass 123.0194-120.3621g = 2.6574
vol 6.518-4.126 ml = 2.392
What volume would 4.32x1023 atoms of Krypton gas occupy at STP?
A 18.5 gram sample of metal was added to a graduated cylinder that had
an initial volume of 45.50 mL. The water level raised to 54.10 mL. Using
this information, calculate the density of the metal. *
Answer:
[tex]d=2.15g/mL[/tex]
Explanation:
Hello there!
In this case, since the density of the metal is computed as shown below:
[tex]d=\frac{m}{V}[/tex]
We need to calculate the volume of the solid by subtracting the final volume and the initial volume of water:
[tex]V=54.10mL-45.50mL\\\\V=8.60mL[/tex]
Thus, we obtain:
[tex]d=\frac{18.5g}{8.60mL}\\\\d=2.15g/mL[/tex]
Best regards!
look at the four chemical reactions
reaction 1:4Na + O ▾ 2 -->2Na ▾ 2O
Reaction 2: 2NaCl—> 2Na+Cl ▾2
reaction 3: CaCO ▾3 —> CaO +CO ▾2
reaction 4: 2KCIO3 ▾3 —> 2KCI + 3O ▾2
which statement identifies the reaction that is different from the rest and explains correctly why it is different?
A.) Reaction 2, because two ions are interchanged
B.) Reaction 2, because two products are formed
C.) Reaction 1, because a single product is formed
D.) Reaction 1, because a single ion is replaced in a compound
Reaction 1 is the one that is different because there is only one product (option C).
In a reaction, there are two main components:
The reactants: Substances at the beginning of the reaction.The products: Substances at the end of the reaction.Moreover, a reaction can include two or more reactants as well as two or more products depending on the substances involved. Let's analyze reaction 1:
Reaction 1: 4Na + O2 → 2Na2OReactants: 4Na and O2Product: 2Na2OThis means in this reaction there is only one product. This does not occur in reactions 2, 3, and 4 because in these there are two products.
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Americium – 242 is a beta emitter. Write an equation for this nuclear reaction and identify the product nucleus.
Answer:
Explanation:
²⁴²₉₅Am ⇒ ₉₆²⁴²Cm + ₋ ₁e .
The product nucleus is Curium .
You are counting red blood cells, which objective will be best to count the number of cells, high power or low power objective and why?
Can someone please HELP MEEEE
Answer:
Low power
Explanation:
Low power would allow for the full image of the red blood cells and would appear as small circles.
How will you describe the difference between heat and temperature?
Answer:
Heat: It is a form of internal energy* obtained because of the random motion and the attractive force of molecules within the substance.
Temperature: It is a quantity that determine which direction the heat energy will flow in.
Explanation:
The type of neuron that carries impulses from the brain are...
What is weather?
a
The atmospheric conditions over many days, weeks, months, and years.
b
The atmospheric conditions for a particular moment in time.
c
The atmospheric conditions forecasted for the next season.
How do plants and animals react to changing environments?
How many liters of oxygen (at STP) are required to form 10.5 grams of hydrogen
Answer:
You'd need 6.55 L of oxygen at STP to form that much water.
Explanation:
Water (3010 g ) is heated until it just begins to boil. If the water absorbs 5.79x105 J of heat in the
process, what was the initial temperature of the water?
Answer:
54 °C
Explanation:
Step 1: Given and required data
Mass of water (m): 3010 gHeat absorbed (Q): 5.79 × 10⁵ JSpecific heat of water (c): 4.184 J/g.°CInitial temperature (T₁): ?Final temperature (T₂): 100 °C (Boiling point of water)Step 2: Calculate the initial temperature of water
We will use the following expression.
Q = c × m × (T₂ - T₁)
5.79 × 10⁵ J = 4.184 J/g.°C × 3010 g × (100 °C - T₁)
T₁ = 54 °C
List 3 metals that could replace lead in the compound Pb(NO3)2 in a single replacement reaction.
Answer:
AKWIJKNZQSOKQPALQALQPALALQLLKILILI
Pls help me I will give you 10 points
If the initial temperature of a movable cylinder was 50 degrees Celsius
with a pressure of 2 ATM and an initial volume of 5 Liters,
what would the new volume be if the temperature was lowered to O
degrees Celsius and the pressure was reduced to 1 ATM?
Answer:
8.45 L
Explanation:
From the question given above, the following data were obtained:
Initial temperature (T₁) = 50 °C
Initial pressure (P₁) = 2 atm
Initial volume (V₁) = 5 L
Final temperature (T₂) = 0 °C
Final pressure (P₂) = 1 atm
Final volume (V₂) =?
Next, we shall convert celsius temperature to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Initial temperature (T₁) = 50 °C
Initial temperature (T₁) = 50 °C + 273
Initial temperature (T₁) = 323 K
Final temperature (T₂) = 0 °C
Final temperature (T₂) = 0 °C + 273
Final temperature (T₂) = 273 K
Finally, we shall determine the new volume. This can be obtained as follow:
Initial temperature (T₁) = 323 K
Initial pressure (P₁) = 2 atm
Initial volume (V₁) = 5 L
Final temperature (T₂) = 273 k
Final pressure (P₂) = 1 atm
Final volume (V₂) =?
P₁V₁ / T₁ = P₂V₂ / T₂
2 × 5 / 323 = 1 × V₂ / 273
10 / 323 = V₂ / 273
Cross multiply
323 × V₂ = 10 × 273
323 × V₂ = 2730
Divide both side by 323
V₂ = 2730 / 323
V₂ = 8.45 L
Thus, the new volume is 8.45 L
Do you think genetic engineering is ethical? Explain why or why not.
Answer:
Yes
Explanation:
One of the top goals of genetic engineering is the improvement of health. Imagine a world without the threat of AIDS or cancer. Those working in the genetics field hope that manipulating the genes of humans will one day enable science to prevent people from contracting these potentially deadly diseases.