What is the key building block of living tissue and ecosystems?
Hope u can help!
Answer:
Your answer is cells. Hope this helps!
EMERGENCY OR I WILL FAIL PLS HELP I WILL MARK BRAINLIEST!!!!
Answer:
1. sublimation
2.melting
3.melting
4.sublimation
Explanation:
melting is a process when solid changes to liquid
Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.
A(n)
image cannot be projected and forms where light rays appear to originate.
Answer:
Eu não sei o que você está dizendo, mas boa sorte
Answer: Virtual
Explanation: A virtual image is an image that can not be formed on a screen. This type of an image is formed when the rays of light appear to meet at a point after reflection or refraction. Virtual images are always erect or upright.
A 350. mL air sample collected at 35 degrees C has a pressure of 556 mm Hg.
What pressure will the air exert if it is allowed to expand to 425 mL at 57 degrees
C? Show your work in the space below.
Answer:
485 torr
Explanation:
Explanation:
We can solve this equation using the combined gas law:
P1V1/T1=P2V2/T2
Remember, always use the absolute (Kelvin) temperature when working with gas equations.
The temperature conversions are
T1=C+273=35o+273=308K
T2=57C+273=330K
Since we're trying to find the final pressure, let's rearrange this equation to solve for
P2:
P2=P1V1T2/T1V2
Our known values:
P1= 550 torr
V1=350mL
T1=308K
V2=425"mL
T2=330K
Let's plug these into the equation to find the final pressure:
The final pressure after it is subjected to these changes is thus 485torr
what is the shortest half life
Answer:
Hey!
Your answer is element A
Explanation:
Using the graph, the element A's emission of radioactive particles ends approximately after 6 years...
A HALF-LIFE IS "HALF" OF THAT TIME PERIOD!
So if the radiation goes for 6 years the half-life is 6 divided by two which gives you 3 years!
The rest however have a longer half-life...
Because they all end at 14 yrs so their half-life in 7 years!
HOPE THIS HELPS!!
Name this compound:
Ca(CO3)
Calcium Carbonate would be your answer!
hope it helps!
Which of the following compounds contains covalent bonds? *
Cs₂O
Fe₂O₃
NaCl
CCl₄
NaCI
Explanation:
I just worked this out the day before
Two friends are arguing about the structure of the universe. Caleb says that the universe is made of many galaxies that are
made of millions of stars and many galaxies that are made of millions of planets. Maria says that he is wrong because
galaxies like the Milky Way are made up of millions of universes with millions of stars.
Which best describes the error(s) that were made in this conversation?
Caleb is incorrect when he says that some galaxies are made of stars and some are made of planets, and Maria is
incorrect when she says that the Milky Way is a galaxy.
Maria is incorrect when she says that galaxies are made up of universes
Caleb is incorrect when he says that some galaxies are made of stars and some are made of planets and Maria is
incorrect when she says that galaxies are made up of universes
Maria is incorrect when she says that the Milky Way is a galaxy
Answer:
i put b but im not that sure
Explanation:
Use the IUPAC nomenclature rules to give the name for this compound - CrPO4.
Answer:
i need help
Explanation:
please helpppppppppp
Select the TRUE statements about the carbon cycle
The carbon cycle is the process in which carbon travels from the atmosphere into organisms and the Earth and then back into the atmosphere.
Plants take carbon dioxide from the air and use it to make food.
Animals eat food and the carbon is stored in their bodies or released during cellular respiration.
Water (H2O) is cycled around the Earth
the carbon cycle is the process in which carbon travels from the atmosphere into organisms and the earth and then back into the atmosphere
Describe the interactions with the Sun, Earth and Moon system that result in Lunar Cycle / Phases.
Answer: The tides are another interaction in the sun-earth-moon system. The tides happen because the moon and sun pull on the oceans, causing them to rise and fall each day. The moon has a bigger effect than the sun because it is closer. The angle of the sun as the earth orbits over the course of a year causes the seasons.
Explanation:
Which of the following is most likely a homogeneous mixture?
O A. A tossed vegetable salad
B. Chunky peanut butter
O C. Chocolate chip cookies
OD. A vanilla milkshake
Answer:
D)A vanilla milkshake
Explanation:
EMERGENCY: I WILL FAIL: PLS HELP WILL MARK BRAINLIEST JUST PLS HELP
Answer:
condensation: moisture builds up on window; dew forms on blades of grass
deposition: snow is made inside a cloud; frst froms on window?
Explanation:
A plant was placed in the corner of a room away from a window. What might you observe about the plant after five days?
Select one:
The plant is leaning toward the window.
The plant is not affected by the light in the window.
The plant is standing straight up from the pot.
The plant is leaning away from the window.A plant was placed in the corner of a room away from a window. What might you observe about the plant after five days? Select one: The plant is leaning toward the window. The plant is not affected by the light in the window. The plant is standing straight up from the pot. The plant is leaning away from the window.
Answer:
1. A. The plant leans toward window.
Explanation:
Plants need light to perform photosynthesis and live. Therefore, this means the plant will always lean toward light in order to survive.
- Hope that helps! Please let me know if you need further explanation.
Answer
Last one I think
Explanation:
What is the oxidation state of Fe(s)
The oxidation state is zero for Fe (s)
What is El Nino and La Nina explained? Please help fast
Answer:
el nino: the boy
la nina: the girl
Explanation:
Answer:
el nino is dinosour la nino is fishcat
Explanation:
Write the beta decay equation for the following isotope: 91 38 Sr? Please write out steps
Answer:
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}Y[/tex]
Explanation:
The unbalanced nuclear equation is
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e \, + \, ?[/tex]
Let's write the question mark as a nuclear symbol.
[tex]\rm _{38}^{91}Se} \longrightarrow \, _{-1}^{0}e \, + \, _{Z}^{A}X[/tex]
The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.
Then
98 = 0 + A, so A = 98 - 0 = 98, and
38 = -1 + Z, so Z = 38 + 1 = 39
Then, your nuclear equation becomes
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}X[/tex]
Element 39 is yttrium, so the balanced nuclear equation is
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}Y[/tex]
Of the following chemical properties , which one is not one that Covalent compounds DO NOT have ?
a
They share electrons between their elements.
b
They have weaker bonds.
c
They have relatviely higher melting and boiling points.
d
Many of these compounds are usallly liquids or gases at room temperature.
Answer:
D. They are usually liquids or gases at room temperature.
Explanation:
Covalent compounds have covalent bonds, meaning that they share electrons between elements and have relatively higher melting melting and boiling points due to the strength of their bonds. However covalent bonds are weaker than ionic bonds which is why B is correct. D is the only incorrect one because it is incorrect and contradicts point C. If a substance has a high melting/boiling point than it is much more likely to be solid at room temperature because of the high temperature it needs to pass in order to be a liquid or gas.
Hope this helped!
2. Find out the enthalpy change of the CH4 from solid Carbon and Hydrogen gas. C (s)+ 2H2 (g)(CH4(g) (H( = ?
Use the following three equations:
C (s)+ O2 (g)(CO2(g) (H( = -393.5 kJ
H2 (g)+1/2 O2 (g)(H2O(l) (H( = -285.8 kJ
CH4 (g)+ 2O2 (g)( CO2(g)+ 2H2O(l) (H( = -890.3 kJ
Answer:
Approximately [tex]-74.8\; \rm kJ \cdot mol^{-1}[/tex].
Explanation:
Number the three reactions with known enthalpy changes:
[tex]\begin{aligned}& {\rm C\; (s) + O_2\; (g) \to CO_2\; (g)} & \quad \Delta H = -393.5\; \rm kJ\cdot mol^{-1}& \quad (1) \\ & {\rm H_2\; (2) + \frac{1}{2} O_2\; (g) \to H_2O\; (l)} & \quad \Delta H = -285.8\; \rm kJ\cdot mol^{-1} & \quad (2) \\ & {\rm CH_4\; (g) + 2\; O_2\; (g) \to CO_2\; (g) + 2\; H_2O\; (l)} & \quad \Delta H = -890.3\; \rm kJ\cdot mol^{-1} & \quad (3)\end{aligned}[/tex].
The goal is to find a way to combine these three reactions to obtain: [tex]\rm C\; (s) + 2\; H_2\; (g) \to CH_4\; (g)[/tex].
Assume that the three known reactions are combined in this way:
[tex]a \times (1) + b \times (2) + c \times (3)[/tex].
That corresponds to:
[tex]\begin{aligned} & a\; \mathrm{C\; (s)} + \left(a + \frac{1}{2}\, b + c\right) \; \mathrm{O_2\; (g)} + b\; \mathrm{H_2\; (g)} + c\; \mathrm{CH_4\; (g)} \\ & \to (a + c)\; \mathrm{CO_2\; (g)} + (b+ 2\,c )\; \mathrm{H_2O\; (l)}\end{aligned}[/tex].
Compare the coefficients of this reaction with that of the desired reaction:
[tex]\rm C\; (s) + 2\; H_2\; (g) \to CH_4\; (g)[/tex].
Note that some species (e.g., [tex]\rm CH_4\; (g)[/tex]) appeared on the wrong side of the equation. Their desired coefficient should be the opposite of their true coefficient. For example, the coefficient of [tex]\rm CH_4\; (g)[/tex] is supposed to be [tex]1[/tex]. However, because it appeared on the wrong side of the equation, its desired coefficient would be [tex]-1[/tex].
The coefficients of species that are not in the desired equation should be zero.
[tex]\begin{array}{|c|c|c|}\cline{1-3}\text{Species} & \text{Coefficient}& \text{Desired Coefficient} \\ \cline{1-3} \mathrm{C\; (s)}} & a & 1 \\ \cline{1-3} \mathrm{O_2\; (g)} & a + (1/2)\, b + c & 0 \\ \cline{1-3} \mathrm{H_2\; (g)} & b & 2 \\ \cline{1-3}\mathrm{CH_4\; (g)} & c & -1\\ \cline{1-3} \mathrm{CO_2\; (g)} & a + c & 0 \\ \cline{1-3} \mathrm{H_2O\; (l)} & b + 2\, c & 0\\ \cline{1-3}\end{array}[/tex].
Solve for [tex]a[/tex], [tex]b[/tex], and [tex]c[/tex]:
[tex]a = 1[/tex].[tex]b = 2[/tex].[tex]c = -1[/tex]. In other words, the third equation is inverted before being added to the other two equations.In other words, the desired equation is equal to [tex]1 \times (1) + 2 \times (2) - 1 \times (3)[/tex].
By Hess's Law, the enthalpy of the desired equation will be:
[tex]\begin{aligned}& 1\times \Delta H (1) + 2 \times \Delta H (2) - 1\times \Delta H(3) \\ &\approx -393.5 + 2 * (-285.8) - (-890.3) \\ &= -74.8\; \rm kJ \cdot mol^{-1} \end{aligned}[/tex].
Which is produced by nuclear fusion?
A. hydrogen
B. electricity
C.
solar radiation
D. gasoline
Answer:
c
Explanation:
4NH3(g) + 3O2(g) --> 2N2(g) + 6H2O(l)
H = 1530.4 kJ
If the temperature of this system is increased, then the equilibrium will shift to the _______ and the amount of N2 gas will _________.
a. left, increase
b. left, decrease
c. right, decrease
d. right, increase
Answer:
the right answer is : d
Explanation:
Because temperature is a cinetic factor.
Review the following chemical equation: Find the molar ratio between C6H6 to
carbon dioxide, CO2. 2C6H6 + 1502 YEILDS 6H20 - 12C02
Answer:
[tex]\frac{1}{6}[/tex]
Explanation:
Molar ratio is defined as the ratio of number of moles of reactants or products in a balanced chemical equation.
In this balanced equation, the number of C6H6 molecules react to form 12 CO2 molecules.
Thus, the molar ratio between C6H6 to carbon will be equal to 2 moles of C6H6 divided by 12 moles of CO2
[tex]\frac{2}{12}\\\frac{1}{6}[/tex]
which is correct? not sure which is right
Answer:
butane
Explanation:
How many moles of O2 can be produced from 1.7 moles of KClO3?
Answer:
2.55 moles
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Index fossils are found throughout the world and come from organisms which existed during limited periods of geologic time. Which of the following best describes what index fossils can be used to determine?
A.
the age of a layer of rock
B.
when an organism first appeared on Earth
C.
how an organism evolved over time
D.
the way an organism went extinct
Answer: A. the age of a layer of rock
Explanation:
Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time.
Index fossils are found throughout the world and come from organisms which existed during the limited periods of geologic time. Index fossils can be used to determine the age of a layer of rock. Thus, the correct option is A.
What is Index fossil?Index fossil is any kind of animal or plant that is preserved in the rock record of the Earth which is characteristic of a particular span of geologic time. A useful index fossil must be distinctive or is easily recognizable, abundant, and have a very wide geographic distribution and also a short range through time.
Index fossils are used to define the geological periods or the age of a layer of rock. These fossils can be defined as the commonly found, widely distributed fossils that are limited in time span. If a person finds an index fossil in a given layer, then he has bounds on the age of the layer.
Therefore, the correct option is A.
Learn more about Index fossils here:
https://brainly.com/question/2495177
#SPJ2
PLZ HELP OR WILL FAIL!!
Label A drop downs are: condensation, melting, sublimation
Label B drop downs are: condensation, melting, sublimation
Label C drop downs are: condensation, melting, sublimation
In the reaction N2 + 3H2 - 2NH3, how many
grams of H, are needed to produce exactly I mole
of ammonia?
A. lg
B. 2g
C.3g
D.4g
Answer:
B. 2g
Explanation:
So first you have to find the mole to mole ratio then convert it to grams if that makes sense. So the mole to mole ratio is 2 ammonia to 3 hydrogen gas. So then after you do that conversion you can solve for grams then. Sorry I am not that great at explaining.
A gas has a volume of 3.00 L at 65.0 C. The same gas has a volume of 11.4 L at 105 C and 1725 mmHg. What was the original pressure of the gas?
when the surface of a mirror curves inward, like the inside of a bowl, it is called a ____.
A) plane mirror
B) convex mirror
C) concave mirror
D) diffuse mirror
Answer:
C
Explanation:
The answer is always C
Answer:C. Concave mirror
Explanation:
When the surface of a mirror curves inward, like the inside of a bowl, it is called c. Concave mirror.
Explain why a small magnet will stick to a refrigerator door, but a nail will not stick.
Answer:
Magnets stick to the fridge door because, underneath the paint, the door is made of steel. Magnets are attracted to certain metals, and if the attraction is strong enough they can hold on even when upside down. ... This means that a magnet will always be attracted to the door. But an iron nail does not have any magnetic properties. So it doesnt get attracted.
Hope this helps, Pls mark as Brainliest!!
A small magnet will stick to a refrigerator door, but a nail will not stick
because magnets attract certain types of metals.
Magnets have a strong magnetic field which is why it attracts metals such
as iron and steel. The refrigerator must have been made with iron or steel
which was why the magnet stuck to it.
Metals such as aluminium and copper aren't attracted by magnets which is
why the nails weren't attracted as a result of it being made with metals which magnets don't attract.
Read more on https://brainly.com/question/19482396
