Answer:
Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.
what type of cells are these?
(Plant or animal)
Answer:
5 is an animal cell, 6 is a plant cell
Explanation:
hope this helps!
definition of atomic number
The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element. The atomic number uniquely identifies a chemical element. It is identical to the charge number of the nucleus. In an uncharged atom, the atomic number is also equal to the number of electrons.
Answer:
its basically represents the number of protons in the nucleus which in a neutral atom equals the number of electrons outside the nucleus and that determines the place of the element in the periodic table
Explanation:
sry i its too long
hope it helps
Clasifica cada uno de los siguientes incisos como sustancia pura (elemento y compuesto) o mezcla (homogénea y heterogénea). Explica brevemente. (a) arroz con leche (b) agua de mar (c) magnesio (d) gasolina
Answer:
Ver explicacion
Explanation:
Un arroz con leche es una mezcla heterogénea porque está compuesto por partículas sólidas de diferentes tipos y tamaños.
El agua de mar es una mezcla homogénea de sustancias todas en la misma fase.
El magnesio es una sustancia pura y es un elemento.
La gasolina es una mezcla homogénea de sustancias comúnmente utilizadas como combustible.
A 220.0 mL sample of helium gas is in a cylinder with a movable piston at 105 kPa and 275 K. The piston is
pushed in until the sample has a volume of 95.0 mL. The new temperature of the gas is 310 K. What is the new
pressure of the sample?
274 kPa
216 kPa
Piston
243 kPa
51.1 kPa
Answer:
Explanation:
what did you get?
Waves that we cannot actually see (unlike ripples in water) and that DO NOT need a medium to travel through belong to which category of waves?
Answer:
electromagnetic waves
Explanation:
The waves that do not need a medium to travel through are known as electromagnetic waves.
What are electromagnetic waves?These waves do not need any medium for their propagation or traveling. The waves have different wavelength and energy factors depending upon their rate of propagation. EMR waves travel from the sun to the earth in space.
Examples of electromagnetic waves are Xrays, gamma rays, radio waves, and more.
Find more information about electromagnetic waves here:
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1.
What is Mendeleev is known for?
A. creating today's atomic model
B. discovering protons
C. publishing the first periodic table
D. discovering Mendelevium
Answer Choice: C
Explanation: Mendeleev is best known for publishing the first periodic table of elements in 1869, revolutionizing the world's understanding of physics and chemistry; and, really almost every aspect of science.
In the above equation how many moles of NO can be made when 43 moles of HNO3 are consumed?
Answer:
rn4y8rg7348y0rp934nrf3
efjewhrf8h934hfr84398wgfyu8o
Explanation:
fe8u34h4n3urhu93q4pirnpqr34uwbry8439br8u3i2rpi34ofreuebue rf ef erf3rw wg
THIS IS A THREE PART QUESTION IF YOU CAN HELP IT WOULD BE REALLY APPRECIATED SO I DONT FAIL.
1. If I add 2.65L of water to 245 grams of sodium acetate, what is the molarity of the NaC2H3O2 solution?
A. 10.8 m
B. 1.13 m
C. 1.08 m
D. 92.4 m
2. If I add 2.65 L of water to 245 grams of sodium acetate, what is the % by mass of NaC2H3O2 in this solution?
A. 8.46%
B.1.12%
C.10.8%
D.9.25%
3. If I add 2.65 L of water to 245 grams of sodium acetate, what is the mol fraction of NaC2H3O2 in this solution?
A. 0.203
B. 0.0846
C. 0.108
D. 0.0199
Answer:
1. B = 1.13M
2. A. 8.46%
3. D = 0.0199
Explanation:
1. Molarity of a a solution = number of moles of solute/ volume of solution in L
Number of moles of solute = mass of solute/molar mass of solute
Molar mass of NaC₂H₃O₂ = 82 g/mol, mass of NaC₂H₃O₂ = 245 g
Number of moles of NaC₂H₃O₂ = 245 g / 82 g/mol = 2.988 moles
Molarity of solution = 2.988 mols/ 2.65 L = 1.13 M
2. Percentage by mass of a substance = mass of substance /mass of solution × 100%
Mass of 2.65 L of water = density × volume
Density of water = 1 Kg/L = 1000 g/L; volume of waterb= 2.65 L
Mass of water = 1000 g/L × 2.65 L = 2650 g
Mass of solution = mass of water + mass of solute = 245 + 2650 =2895 g
Percentage by mass of NaC₂H₃O₂ = 245/2895 × 100% = 8.46%
3. Mole fraction of NaC₂H₃O₂ = moles of NaC₂H₃O₂/moles of solution
Moles of water = mass /molar mass
Mass of water = 2650 g; molar mass of water = 18 g/mol
Moles of water = 2650 g / 18 g/mol = 147.222 moles
Moles of solution = moles of solute + moles of water = 147.222 + 2.988 = 150.21
Moles of NaC₂H₃O₂ =2.988 moles
Moles fraction of NaC₂H₃O₂ =2.988/150.21 = 0.0199
Is hydrogen a metal or a nonmetal? How many valence electrons does a hydrogen atom have?
Answer:
hydrogen is a non-metal and it has 1 valence electron
Explanation:
You can find the valence electrons on the bottom left of your periodic table, it is under the atomic number. Hydrogen is a non-metal because hydrogen conducts heat and electricity poorly.
State and explain the three basic properties of element
Answer: Some are solid, some are gaseous, a few are liquid. Some are metallic: they have a peculiar lustre; some are coloured (like sulfur) or colourless. Some have a low density; some have a high density. Some are malleable and ductile; some are brittle. Some conduct electricity and heat well; some don’t.
Many metals tend to have structural uses. Nonmetallic elements less so.
Metals tend to have crystal forms featuring close-packed centro-symmetrical structures. Nonmetallic elements tend to have crystal structures featuring more open and directionally packed structures.
Some are especially toxic; some are essential to life; some are both depending on exposure level.
Most are stable; some are less so.
Some elements are highly reactive; some are almost inert (helium, neon, and argon may be completely inert in ambient conditions).
Many metals have basic oxides; quite a few oxides of nonmetallic elements form acids when they are dissolved in water. Some elements can go both ways.
There are many generalisations you can make about metallic and nonmetallic elements, and quite a few exceptions at the margins.
Explanation:
State and explain the three basic properties of element.
Answer :-Some properties of an element can be observed only in a collection of atoms or molecules of the element. These properties include color, density, melting point, boiling point, and thermal and electrical conductivity.
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Answered by - ItzMaster
Balance the following equation: Fe2O3 + H2O --> Fe(OH)3
A.3,2,1
B.2,2,3
C.1,3,2
D.5,2,10
Answer:
answer is c
Explanation:
hope it helps!!!
Show work for all math problems. Make sure to have the correct unit and significant figures in your each answer.
Convert 2.35 atm to mmHg.
Given the reaction: HNO2 (aq) <-> H+ (aq) + NO2- (aq); write the ionization constant for the reaction.
Answer:
see explanation
Explanation:
HNO₂ ⇄ H⁺ + NO₂⁻
Ka = [H⁺][NO₂⁻]/[HNO₂]
zinc + hydrogen arsenate—>
What type of reaction is this? (Synthesis, Decomposition, or Single Replacement?
Answer:
Single Replacement
Explanation:
im just smart lol
3. The hydroxide-ion, [OH-], concentration in a detergent solution is 1.0 x 10-3 M. What is [H+] concentration in the detergent solution?
A) 1.0 x 10^-11 M.
B) 1.0 x 10^-9 M.
C) 1.0 M
D) 0.001 M
Answer:
c
Explanation:
h
At STP (101.3 kPa, 0 °C), what volume would 2.00 moles of oxygen gas occupy? The gas constant is 8.31
Answer:
44.8 L
Explanation:
Ideal Gas Equation -
i.e.,
PV = nRT
where,
P = pressure
V = volume
n = moles
R = universal gas constant
T = temperature
Using the information given in the question, Volume of the gas can be calculated -
P = 101.3 kPa
V = ?
n = 2.00 moles
R = 8.31
T = 0 degree C = 273.15 K
Using the above data, and putting the data in the respective formula -
PV = nRT
101.3 kPa * V = 2.00 moles * 8.31 * 273.15 K
V = 44.8 L
Hence, the volume of the given gas = 44.8 L
What fossil helped support Wegener's hypothesis of continental drift?
A. Gondwanaland
B. Kannemeyerid
C. Mesosaurus
D. Glossopteris
Answer:
Glossopteris
Explanation:
Glossopteris is a fossil fern that helped support Wegener's hypothesis.
Hope this helps! Have a great day!
A gas is most likely to change the liquid phase in the pressure of the gas
Answer: if pressure rises in closed vessel and temperature is low enough,
Gas may condense to liquid state
Typically, this happens when we raise the pressure at room temperature, but there are other situations that aren't covered, including lowering the temperature at room pressure.
What is temperature?Temperature is defined as a measurement of an object or substance's warmth or coldness in relation to a standard value. As opposed to extensive characteristics, like mass or volume, temperature is referred to as an intense property—one that is independent of the quantity of matter being considered—along with pressure, density, and other comparable properties.
If the temperature is low enough and pressure rises in a closed vessel, A gas can turn into a liquid form.
Thus, typically, this happens when we raise the pressure at room temperature, but there are other situations that aren't covered, including lowering the temperature at room pressure.
To learn more about temperature, refer to the link below:
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Study the map. Then use the drawing tool to create a model of how the two air masses look when they interact at front 1.
Answer: Picture
Explanation: I got it right
Answer:
2 and 3 look like a cold front in front of 1.
Explanation:
3 is an occluded front which occurs when a cold air mass devours a warm air mass and then collides with another cold mass. 2 is a warm air mass, and 1 is a cold air mass.
how does salt alter the boiling point and freezing point of water
Answer:
adding salt is like adding an impurity therefore the boiling point might increase from 100°c to maybe 102°c
What type of substances can we separate using electrolyisis and why?
Answer:
ionic substances because they contain charged particles
Science 3 questions with brainliest
Answer:
#1 is c #2 is d and #3 isd
Explanation:
how many daughter cells would be produced if 32 cells undergo meiosis
Answer:
The meiosis process can for up to 4 daughter cells
Barium + Aluminum nitrate —> makes what ?
Answer:
Aluminum sulfate with barium nitrate to produce burin and aluminum nitrate
Aluminium hydroxide and barium nitrate are produced as a result of the chemical reaction between barium and aluminium nitrate. The reaction's balanced equation is as follows: [tex]2 Al + 3 Ba (NO_3)_3 \rightarrow 3 Ba(NO_3)_2 + 2 Al(OH)_3[/tex]
Chemical reactions are essential natural processes that take place and are in charge of the innumerable alterations and transformations we experience every day. They include the forming and breaking of chemical bonds between atoms, which causes the atoms to be rearranged to produce new compounds with various properties. The concepts of mass and energy conservation control chemical processes. The idea of balanced chemical equations came about because the total number of atoms of each element involved in a reaction stays constant both before and after the reaction. Aluminium hydroxide and barium nitrate are produced as a result of the chemical reaction between barium and aluminium nitrate. The reaction's balanced equation is as follows: [tex]2 Al + 3 Ba (NO_3)_3 \rightarrow 3 Ba(NO_3)_2 + 2 Al(OH)_3[/tex]
To know more about chemical reaction, here:
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What is the density of krypton gas (MM = 83.8 g/mol) at 3.00
atm and 100. °C?
g/L
Answer:
8.21
Explanation:
Which unit is commonly used for measuring pressure?
O m3
O bar
O N/m3
O Celsius
Answer:
3
Explanation:
Answer:
bar
Explanation:
yes
11. A chemical reaction happens when chemicals combine to form a new _______
Answer:
substances
Explanation:
A chemical reaction happens when substances break apart or combine to form one or more new substances.
^Hope it helps, Hazel^
Which do you think has the greater total kinetic energy?
a. The molecules of the water in the teacup
b. The molecules of the water in the bathtub
Answer:
a The molecules of the water in the teacup
hope it helps
What is the charge of a Li ion?
A. +1
B. +2
C. -1
D.-2
Answer:
A
Explanation:
because the charge of Li ion is +1 well I don't know the explanation yet but I'm sure about the answer
WILL MARK BRAINLEST
Which of the following are sources of greenhouse gasses? Select all that apply
a
Bike Riding
b
Cow Farts
c
Growing Trees
d
Burning Coal
e
Car Exhaust
Answer:
b and c
Explanation:
sorry if i'm wrong
Answer:
b, c, d, e
Explanation: