Answer:
120 km
Explanation:
If he goes 20km/h and travled for 6 hours then he would have gone 120 km. 20 multiplied by 6
Without the atmosphere, life on Earth would not be possible. Which of the following is NOT an explanation for how Earth’s atmosphere protects life on the planet?
A. It allows visible light to pass through completely.
B. It contains gases that filter out ultraviolet radiation.
C. It keeps Earth warm by trapping in heat.
D. It protects life from ultraviolet rays of light
Answer:
B
Explanation:
IM A CHEMISTRY WIZZZZ
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I hope u get full marks on your paper/test/quiz or whatever!
There is a 20 percent chance so stay positive!
Answer:
D
Explanation: ultraviolet rays are harmful to humans
How many atoms are in 355 mol Na?
Answer:
2.138 x 10^26 atoms Na
Explanation:
atoms Na = 355 mol Na x (6.022 x 10^23 atoms Na/1 mol Na) = 2137.81 x 10^23 atoms Na = 2.138 x 10^26 atoms Na
What is crystallization how can you obtain bigger crystals
Answer:
Crystals that grow more slowly, tend to be larger. For crystals that were grown by slow cooling of the solvent: it usually improves the quality and size of the crystals, if the solution is slowly warmed up until alomst all crystals are dissolved again and than cooled dwon a second time very slowly.
Explanation:
rystallization or crystallisation is the process by which a solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some of the ways by which crystals form are precipitating from a solution, freezing, or more rarely deposition directly from a gas.
The diagrams P, Q and R show the atoms in a compound, an element and a mixture,
but not necessarily in that order.Which row of the table correctly identifies P, Q and R?
look at the photo
Answer:
C.
Explanation:
A mixture contains two or more substances.
A compound contains elements in a fixed ratio.
P = Element
Q = Compound
R = Mixture
The correct order is C.
Describe how different environments support different
varieties of organisms
Answer:
How is an environment able to support different varieties of organisms? ... It provides all the necessary conditions, such as temperature, space, water and food resources, oxygen and carbon dioxide, that suit the needs of the organisms. Examples of habitat include forests, mountains, bodies of water, and even puddles.
Explanation:
At what temperature does water freeze?
Answer:
32 degrees
Explanation:
Is Oxygen more reactive than Beryllium
Why do you think the astronomical unit is not used to measure distances on earth?
Answer:One Astronomical Unit is the distance between the Earth and the Sun, this acts as a sort of a cosmic metre stick. Astronomers don't and cannot measure distances. Distances are merely inferred from what actually has been measured, such as an angle, a relative luminosity, a time period
Explanation:
Answer:
you would have to use decimals in the quadrillionths if you measure in meters. so 11 0s before the number
For the reaction HNO3 + Mg(OH)2→ Mg(NO3)2 + H2O, how many grams of magnesium nitrate are produced from 8.00 mol of nitric acid, HNO3? Balance the equation
Answer:
2HNO3 + Mg(OH)2 --> 2H2O + Mg(NO3)2
593.2 grams Mg(NO3)2
Explanation:
First, balance the equation
The first thing I notice is that there are 2 nitrates on the reactant side so I would put a 2 in front of HNO3. Now the problem is that there are 4 hydrogens on the reactants side, so add a 2 to H2O.
Next is stoichiometry
We are looking for Mg(NO3)2 so use the balanced equation to create a mole ratio and then convert to grams.
8 mol HNO3 * 1 mol Mg(NO3)2/2 mol HNO3 * 148.3 g Mg(NO3)2/1 mol Mg(NO3)2 = 593.2 grams Mg(NO3)2
593.2 grams of Magnesium Nitrate [[tex]Mg(NO_3)_2[/tex]] are produced.
Balancing the equation we get:
[tex]2HNO_3 + Mg(OH)_2 = 2H_2O + Mg(NO_3)_2[/tex]
Here we can see that [tex]2HNO_3[/tex] produces [tex]1Mg(NO_3)_2[/tex]
It implies that to make 1 mole of [tex]Mg(NO_3)_2[/tex] we need 2 moles of [tex]2HNO_3[/tex]
Therefore in 8 moles of [tex]2HNO_3[/tex] , 4 moles of [tex]Mg(NO_3)_2[/tex]will be produces.
Now, 1 mole of [tex]Mg(NO_3)_2[/tex] = 148.3 g
4 moles of [tex]Mg(NO_3)_2[/tex] = 4 × 148.3 g = 593.2 g of magnesium nitrate will be produced.
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A 200 g block of a substance requires 520 J of heat to raise its temperature from 25°C to 45°C.
Use the table to identify the substance.
The answer is gold.
Explanation:Substance: Specific Heat (C) in joules per gram/degrees centigrade:
Water (ice) 2.05
Iron 0.46
Aluminium 0.90
Gold 0.13
Copper 0.39
Ammonia (liquid) 4.70
Ethanol 2.44
Gasoline 2.22
Water (liquid) 4.18
Water (vapor) 2.08
Air (25 degrees Celsius) 1.01
Oxygen 0.92
Hydrogen 14.30
To know that we clear the equation q=m*C*Δt for the specific heat (C) and solve the equation. Keep in mind that we need to use the heat (520 J) in Joules since the values from the question and the table are in Joules.
q/m∗ΔT = C = 520J/200g∗(45degC−25degC) =
0.13J/gdegC
As you can see, the substance that has this specific heat is GOLD.
The value of specific heat for the given data in the question will be for gold:-
[tex]C= 0.13\ \dfrac{J}{g^oC}[/tex]
What will be the Specific heat of the material?Specific heat can be defined as the amount of heat one kg or gram substance can absorb or release for a unit temperature difference.
The formula for the heat will be:-
[tex]Q=mc\Delta T[/tex]
m= Mass of substance
c= specific heat of the substance
[tex]\Delta T[/tex]= Temperature difference
Now the given data is
m= 200 g
Q= 520 J
[tex]\Delta T[/tex]= (45-25)=20
[tex]Q=mc\Delta T[/tex]
[tex]520=200\times C\times 20[/tex]
[tex]C= \dfrac{520}{200\times 20} =\dfrac{520}{4000} =0.13\ \dfrac{J}{g ^oC}[/tex]
Since the value of specific gold is [tex]0.13\ \dfrac{J}{g ^oC}[/tex]
Thus the value of specific heat for the given data in the question will be for gold:-
[tex]C= 0.13\ \dfrac{J}{g^oC}[/tex]
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Which of the following diagrams represents a single
replacement reaction?
Explanation:
i think the answer is....b
The diagram that represents single replacement reaction is:
b.
Single replacement reaction:This reaction is also known as displacement reaction. It is a reaction in which one element is substituted for another element in a compound. When a replacement reaction occurs, a new aqueous compound and a different pure element will be generated as products. For example:
[tex]2HCl(aq)+Zn(s)--->ZnCl_2(aq)+H_2(g)[/tex]
Thus, option b is correct.
Find more information about displacement reaction here:
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Can someone please help me with this question.
Answer:
Birds evolved from a group of meat-eating dinosaurs called theropods. That's the same group that Tyrannosaurus rex belonged to, although birds evolved from small theropods, not huge ones like T. rex.
Answer:
we haven't done anything to study the roots of the bird yet
Please answer these as quick as possible! thank you!! Q4. What is the name of group 1 in the periodic table?
Q5. What is the name of group 7 in the periodic table?
Q6. What is the name of group 8 (or group-0 as it's sometimes called) in the periodic table?
Answer:
1st group-alkali metals
7th group-halogen group
8th group- noble gas group
Answer:
4. Group 1 in periodic table is called alkali metals.
5. Group 7 in periodic table is called halogens.
6. Group 8 or 0 in periodic table is called noble gases.
What is the empirical formula of a compound that contains 85% Ag and 15% F by mass?
Answer: AgF
Explanation: 85 / 108 (the relative atomic mass of Ag) = 0.79
15 / 19 (the RAM of F) = 0.79
This is a 1:1 ratio so the empirical formula is AgF.
AgF is the empirical formula of a compound that contains 85% Ag and 15% F by mass.
What are moles?A mole is defined as 6.02214076 × [tex]10^{23}[/tex]of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
Molar mass of Ag =108 amu
[tex]Moles = \frac{mass}{molar \;mass}[/tex]
85 ÷ 108 = 0.79
The molar mass of F = 19amu
[tex]Moles = \frac{mass}{molar \;mass}[/tex]
15 ÷ 19 = 0.79
This is a 1:1 ratio so the empirical formula is AgF.
Hence, AgF is the empirical formula of a compound that contains 85% Ag and 15% F by mass.
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Write the position of metals, non - metals and metalloids in the periodic table.
Answer:
The metals are to the left of the line (except for hydrogen, which is a nonmetal), the nonmetals are to the right of the line, and the elements immediately adjacent to the line are the metalloids.
Hello! Can you please help me do this question? I have to pick two but I’m not really sure what to pick..
Answer:
B and D
Explanation:
it is B and D because in no gravity if you change the size of the ball it does not change anything. and if you swing fast it does not change anything but the speed. if you change the angle it is just the same modle but different angle
Answer:
D, and E
Explanation:
they may not be correct but the answers seem correct. please tell me If I'm wrong.
please help >>>>>>>>>>>
Answer:
Explanation:
mass of 1mole of brick = mass of 1 brick x avagadro number
= 4 kg x 6.022 x 10^23 bricks = 2.4 x 10^24 kg
No. of moles of bricks have a mass equal to the mass of the earth
= mass of earth / mass of 1 mole of brick
= [ 6 x 10^27 ] / [ 2.4 x 10^24 ]
= 2.5 x 10^3
= 2500 moles
Select the correct answer from each drop-down menu.
An atom has 9 electrons and 9 protons at the start. If it loses 2 electrons, the net charge on the atom will be_____. If the atom gains 4 electrons, the net charge will be_____.
Answer:
Answer: If the atom loses 2 electrons, the net charge on the atom will be 2+
If the atom gains 4 electrons, the net charge on the atom will be 4-
Explanation:
An atom is smallest unit of a matter or substance.It consist of three subatomic particles : electrons, protons, neutrons.
Protons are positively charged, neutrons are neutral and both are located in nucleus where mass of an atom is concentrated.
Electrons are negatively charged and are located outside the nucleus where they orbit in different energy levels around the nucleus.
In an atom, when electrons are lost, the atom gains a positive charge and forms cation. In an atom, when electrons are gained, the atom occupies a negative charge and forms anion.
Thus an atom with 9 electrons and 9 protons will be electrically neutral.
On losing 2 electrons, there will be 7 electrons and 9 protons will have 2+ charge.On gaining 4 electrons, there will be 13 electrons and 9 protons will have 4- charge.
Can we create matter? Why or why not?
Answer:
The first law of thermodynamics doesn't actually specify that matter can neither be created nor destroyed So yes we can create matter because matter is every where buildings ,structures etc. So the answer is yes!
Explanation:
Hope this helped!ヾ(•ω•`)o❤
How much KNO3 can be dissolved at 50 C in 100g of water?
Answer:
Initially there is 100 g of potassium nitrate in solution, at 50 °C the solubility is 84 g/100g (original data or graph), so 16 g will have crystallised out
Explanation:
PLEASE ANSWER ASAP I WILL GIVE BRAINLIEST!!
Answer: It’s Lower
What can you say about the pH of a carbonic acid solution compared to that of a sulfuric acid soloution with the same contention: Strong acids dissociate fully in water to produce the maximum number of [tex]H^{+}[/tex]ions. The pH levels of strong acids are smaller than those of low acids, which is why the reactions rates for strong acids are greater than the reactions of weak acids with products like metals, metal carbonates, etc. Meaning The pH Level is lower.
If you place a piece of iron at 90 °C into water that is 25 °C, in which direction heat will flow?
Answer:
Determine the final temperature when a 25.0 g piece of iron at 85.0 °C is placed into 75.0 grams of water at 20.0 °C.
First some discussion, then the solution. Forgive me if the points seem obvious:
a) The colder water will warm up (heat energy "flows" in to it). The warmer metal will cool down (heat energy "flows" out of it).
b) The whole mixture will wind up at the SAME temperature. This is very, very important.
c) The energy which "flowed" out (of the warmer water) equals the energy which "flowed" in (to the colder water)
Explanation:
Aqueous sodium hydroxide forms a light blue precipitate. What is the formula of the blue precipitate?
Answer:
Cu2+(aq) + 2OH-(aq) => Cu(OH)2(s)
Explanation:
Use of aqueous sodium hydroxide is a precipitation reaction to test for anions or cations. Aqueous sodium hydroxide in a precipitate test forms a insoluble precipitates along with some colors characteristics.
Aqueous sodium hydroxide (NaOH) when mixed with copper(II) (Cu2+) forms a blue precipitate. The formula is as follows:
Cu2+(aq) + 2OH-(aq) => Cu(OH)2(s)
find the pH of a 0.79 M solution of NH3,a weak base,if it has a Kb of 4*10 -5
Answer:
Cat
Explanation:
Bcuz I said so that it's a cat
respond if you got a min to help me with my problem
Answer:
I mean i dont know......
Explanation:
PLEASE HELP ASAP I WILL GIVE BRAINLIEST!
Consider the reaction pathway graph below.
The rate increases by a factor of 9 when the concentration of A triples. The rate triples when the concentration of B triples. What is the new rate law for the reaction?
A) endothermic because Hrxn=-876.8 kJ
B) endothermic because Hrxn=876.8kJ
C)exothermic because Hrxn= -1099.6kJ
D) exothermic because Hrxn=1099.6kJ
Answer:
B is the answer
Explanation:
What is the molar mass for MgO?
Answer:
40.3044 g/mol
Explanation:
Which of the following statements about atoms is true?
A) atoms can be seen with the human eye
B)atoms can be divided or destroyed in chemical reactions or through physical changes
C) in a chemical reaction, new atoms can appear that weren’t there to start with
D)atoms make up substances
Answer:
D
Explanation:
Atoms make up all matter on earth, basically atoms make up everything, even air.
15) When dilute sulfuric acid is added to zinc metal the products of the reaction are
A zinc oxide + water + hydrogen
B zinc oxide + hydrogen
C zinc sulfate + water + hydrogen
D zinc sulfate + hydrogen
Mitosis creates
that are
in chromosome number.
A) Somatic Cells ; Haploid
B) Somatic Cells: Diploid
C) Gametes: Haploid
D) Gametes ; Diploid
