What makes plants the beginning of the food chain?
please answer my question aswell as my last one!
Answers
Answer: A
Explanation:
i just took the quiz and it was right!
Related Questions
If the half life of iridium-182 is 15 years, how much of a 3 gram sample is left after 2 half-lives?
A) .57 grams
B) .70 grams
C) 2.25 grams
D) .75 grams
Answers
Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182, [tex]t_{(1/2)}[/tex] = 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;
[tex]N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}} }[/tex]
For two half lives, t = 2 × [tex]t_{(1/2)}[/tex]
∴ t = 2 × 15 = 30
[tex]\dfrac{t}{t_{(1/2)}} = \dfrac{30}{15} = 2[/tex]
[tex]\therefore N(t) = 3 \times\left (\dfrac{1}{2} \right )^2 = 0.75[/tex]
∴ The amount left, N(t) = 0.75 grams
Write the complete and net ionic equations for the following reactions. If only the reactants are given, predict the products and balance the equation first.
Answers
Explanation:
u can put them in order crossed are spectator ions. hope this helps:)
Describe two situations in which you observed or performed an energy transformation. For each situation, name the starting form of energy and an ending form of energy.
Answers
Answer:
The Sun transforms nuclear energy into heat and light energy.
Our bodies converting chemical energy in our food into mechanical energy for us to be able to move.
An electric fan transforming electrical energy into kinetic energy.
If the pressure of a 2.00 L sample of gas is 50.0 kPa, what pressure does the gas exert if its volume is decreased to 20.0 mL?
Which equation should you use?
Answers
__________________________________________________________
Which equation should you use?
B. P₁V₁=P₂V₂
What is the new pressure?
✔ 5000 kPa
__________________________________________________________
Explanation:The problem gives initial volume (2.00 L), final volume (20.0 mL), and initial pressure (50.0 kPa). Then it asks to find the final pressure. Answer B has all these variables, with P₁=initial pressure, P₂=final pressure, V₁=initial volume, and V₂=final volume. Plug the given values into the equation and then solve for the unknown value, which is P₂, final pressure.
When plugging in the values, use consistent units. 2L=2000 mL, I chose to make the consistent unit in mL. You'll get the same answer if you choose to use L as the consistent unit.
[tex]2000*50=20*P2[/tex]
[tex]100000=20*P2[/tex]
Divide both sides by 20
[tex]100000/20=(20*P2)/20[/tex]
[tex]5000=P2[/tex]
Here's a photo of Edge just incase.
Who made the first periodic table of the elements?
O A. Ernest Rutherford
O B. Dmitri Mendeleev
O C. Niels Bohr
O D. Henry Moseley
Answers
The periodic table was invented by Russian chemist Dmitri Mendeleev in 1869.
Answer:
B. Dmitri Mendeleev
Explanation:
Which atom attracts electrons most strongly? br F Rb
Answers
Fluorine has the highest electronegativity in comparison to other elements therefore, the F atom attracts electrons most strongly.
What is electronegativity?The electronegativity of an atom measures the tendency of an element to attract the bonded electrons pairs towards itself. The electronegativity of an atom is determined with respect to another bonded atom.
Electronegativity can be described as a chemical property of an atom or a functional group to attract electrons toward itself. The electronegativity of an atom depends on the atomic number and the distance of valence electrons from the charged nuclei.
When two different atoms are bonded through a bond. More electronegative will attract the electron density of the bond towards itself.
As we know, the electronegativity decreases as we move down the group in the periodic table. Fluorine is the most electronegative element in the periodic table therefore, Fluorine (F) will attract the electrons toward it most strongly.
Learn more about electronegativity, here:
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What charge would Balloon #2 have? How did you determine this?
Answers
Answer:I belive it would be attracted seeing as how there are more magmatic charges on that side of no 2 and how there are more positive charges on the middle side of ballon no1.
Explanation:
HELP ASAAAAP 40 MINS LEFT AAA!
Geometric isomers have profound effects on the physical properties of compounds. Naturally occurring fatty acids generally adopt a cis geometry. What's one physical property affected by this geometry?
A)
Color
B)
Taste
C)
Smell
D)
Melting point
Answers
what is the molecular weight of a gas which diffuses 1/50 as fast as hydrogen
Answers
the rows from left to right in the periodic table is called what
Answers
Answer:
The periodic table has rows that go left to right and columns that go up and down, just like any other grid. The rows are referred to as PERIODS, while the columns are referred to as GROUPS.
Explanation:
Which of the following represents an element ? H2O H2 NaCl CaCO3
Answers
Answer:
H₂
Explanation:
H₂ is hydrogen in its elemental form.
H₂O, NaCl, and CaCO₃ are all examples of elements added together to create compounds.
A test light with an electrical resistance of 9.00 S2 draws a current of 1.50 A when
it is connected to an electrical source. How much power does the light use?
Answers
Answer:
20.25 W
Explanation:
Applying,
P = I²R.................... Equation 1
Where P = Power, I = current drawn by the test light, R = Resistance of the test light
From the question,
Given: I = 1.5 A, R = 9.00 Ω
Substitute these values into equation 1
P = (1.5²)(9)
P = 2.25×9
P = 20.25 W
I need to know the coefficient order
Answers
Explanation:
in mathematics use Pascal triangle
A gas fills up a container that has 2.5L has a pressure of 3.5 atm. If the gas gets transferred to a container that holds 4L, what would the new pressure be?
Answers
1. BaBr2(aq) + H2SO4(aq) →?
please balance the equation and predict the products
Answers
Answer:
BaBr2 (aq) + H2SO4 (aq) → BaSO4 (s) + 2 HBr (aq)
Explanation:
This is a precipitation reaction: BaSO4 is the formed precipitate.
Determine the volume of a helium balloon given the balloon was filled from a container 0.15L of gas at 2 atm if the new pressure is 0.97 atm. Assume constant temperature.
Answers
Answer:
The volume of the helium balloon is 0.306 L.
Explanation:
Boyle's law states that the volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure. That is, if the pressure increases, the volume decreases, while if the pressure decreases, the volume increases.
Mathematically, Boyle's law indicates that the product of pressure and volume always has the same value:
P*V= k
Assuming that you have a certain volume of gas V1 that is at a pressure P1 at the beginning, by varying the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1*V1= P2*V2
In this case:
P1= 2 atmV1= 0.15 LP2= 0.97 atmV2= ?Replacing:
2 atm* 0.15 L= 0.97 atm* V2
Solving:
[tex]V2= \frac{2 atm* 0.15 L}{0.97 atm}[/tex]
V2= 0.306 L
The volume of the helium balloon is 0.306 L.
The photograph below shows the East African Rift Valley in Africa. Which tectonic movement
of Earth’s crust is most likely responsible for this feature?
Answers
Answer:
divergence of continental crust
Explanation:
Vhon Anadome
Atomic nucleus questions
Which of the following decay processes results in the largest change in mass of a nucleus?
Choose 1 answer:
А
Beta decay
Gamma decay
Neutron emission
D
Alpha decay
Answers
Answer:
d
Explanation:
Aqueous solutions of a strong acid and a weak acid of equal concentrations are compared. Which of the following statements are true?
I. The strong acid reacts with a metal oxide but the weak acid does not
II. The weak acid is less disassociated than the strong acid
III. The strong acid has a greater conductivity that the weak acid.
Answers
Answer:
Explanation:
lime water turns milky when carbon dioxide gas passed through it and on further exposure to carbon dioxide the milkiness disappear, why
Answers
Resultant carbon dioxide passed through limewater in the right tube, producing a milky solution due to precipitation of the insoluble suspension of calcium carbonate: ... The milkiness disappears since calcium bicarbonate is water-soluble.
Write the nuclear equation for the beta decay
of calcium-45.
Answers
Answer:
on https://www.ck12.org/book/peoples-physics-concepts/section/20.1/
Explanation:
it shows for calcium 45 and maybe a possible equation on 3/4th's scroll down?
when potassium chloride is dissolved in water *
a)heat is given off
b)heat is taken in
c)temperature stays same
Answers
Answer:
Option B . heat is taken in
Answer:
B
Explanation:
we need to eat,drink,and sleep to be healthy
Write a nuclear equation for the beta decay of Promethium-165
Answers
Answer:
see your answer in pic
Explanation:
There can be emissions of radiations like gamma radiation. There can be emission of particles too like alpha particle. Therefore, the nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
What is nuclear decay?Nuclear decay is process in which the radioactive element releases particles or radiations. Alpha particles is ⁴₂He. Alpha particle is nothing but helium particle. The kinetics that is related to nuclear decay is of first order.
The nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
Beta decay of Promethium-165 is the emission of electron particle from the given isotope. the product is Samarium ₆₂Sm¹⁶⁵.
Therefore, the nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
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write a chemical equation for action of HBr on ethanol
Answers
answer:
hope this one helps have a great day !
Suppose I have enough ingredients to make 25 cookies, but when I go to bake them, I only get 5. What percent yield did I obtain?
Answers
Answer:
Explanation:
What is the "theoretical yield" of cookies from each of the "reactants?"
Theor. yield from eggs
=
12
eggs
×
24 cookies
1
egg
=
288 cookies
Theor. yield from vanilla
=
24
tsp vanilla
×
24 cookies
1
tsp vanilla
=
576 cookies
Theor. yield from salt
=
82
tsp salt
×
24 cookies
0.5
tsp salt
=
3936 cookies
Theor. yield from baking soda
=
84
tsp baking soda
×
24 cookies
0.5
tsp baking soda
=
4032 cookies
Theor. yield from chocolate chips
=
3
cups chocolate chips
×
24 cookies
1.333
cups chocolate chips
=
54 cookies
Theor. yield from sugar
=
11
cups sugar
×
24 cookies
0.5
cup sugar
=
528 cookies
Theor. yield from brown sugar
=
4
cups brown sugar
×
24 cookies
0.5
cup brown sugar
=
192 cookies
Finally, "we leave it as an exercise for the student" to calculate that
Theor. yield from margarine = 72 cookies
b. Identify the limiting reactant
The limiting reactant is the amount of chocolate chips because they can produce the smallest amount of cookies.
c. Determine the theoretical yield
The theoretical yield is 54 cookies, because that is all you can get from the chocolate chips provided.
The percent yield obtained on baking the cookies is 20 % and the theoretical yield is 25 cookies.
What is percent yield?Percent yield is defined as the ratio of actual yield to the theoretical yield multiplied by 100. If the actual and theoretical yield are same then the percent yield is 100%.If actual yield is less than the theoretical yield then the percent yield is less than 100%.Reason of this condition arising is the incompletion of reaction or loss of sample during recovery process.
In cases where percent yield is over 100% it indicates that more sample is recovered than the predicted amount.This condition arises when there are other simultaneous reactions taking place leading to the formation of product. It can also arise if there is incomplete removal of impurities from the sample .
As cookies obtained is 5 it is observed yield while 25 is theoretical yield so the percent yield, 5/25×100=20%.
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How would the balloons interaction with each other change if the balloons were moved further apart? Explain.
Answers
Explanation:
It is known that like charges repel each other and unlike charges attract each other.
As the balloons are facing each other with like charges so they will repel each other. Hence, they will move apart.
But when balloons were moved further apart then interaction between them will decrease and then there will be no force of repulsion or force of attraction.
Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state
compare with the temperature at the end of the change?
Answers
Answer:
The temperature on the graph is higher at point 5 than at point 1. The correct answer is the last answer choice that you showed.
Explanation:
The temperature at point 1 is -10 degrees Celsius, while the temperature at point 5 is 120 degrees Celsius. This is a 1300% increase.
See the calculation here: https://www.calculatorsoup.com/calculators/algebra/percent-change-calculator.php?v_1=-10&v_2=120&action=solve
I hope this helps.
calculate the oxidation numbers of the elements in this equation
2 Al2O3 → 4 Al + 3 O2
Answers
Explanation:
Answer
Open in answr app
The rule used here is that the algebraic sum of the oxidation numbers of all the atoms a molecule is zero.
Al2O32× ( oxidation number of Al)+3× ( Oxidation number of O ) = 0
2× ( Oxidation number of Al) +3(−2)=0
2× ( oxidation number of Al) +6
∴ Oxidation number of Al =+3
Witch part of an atom is mostly empty space?
Answers
Fill in the coefficients that will balance the following reaction:
