Answer:
145 hours
Explanation:
Since one hour of riding a bicycle takes up 505 kcal of energy. It is also stated that one gram of body fat is equal to 7.70 kcal. Also, it is given that 1 pound of body fat is equal to 454 g.
Hence;
1 Ib= 454 g
21 Ib= 21 × 454/1 = 9534 g
But
1g of body fat = 7.70kcal
9534 g of body fat = 9534 × 7.70 kcal/1 = 73411.8 kcal
If 505 kcal is lost in 1 hour
73411.8 kcal is lost in 73411.8 kcal × 1hour/505k cal = 145 hours
Sodium easily combines with chorine is reactivity
answer
yes
Explanation:
Plz help! The best answer will be marked as brainliest!
Make a funny sentence of alloys for Magnesium
Here is an example for Mercury, it HAS to for Magnesium
“I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon”
Answer:
Sometimes the whole alloy in a uniform is a solid solution
A student accidentally left a bottle of ammonia unclosed in the corner of a laboratory
After a few minutes the entire laboratory smelled of ammonia.
Which process has occurred?
A
Brownian motion
B
Diffusion
с
Evaporation
D
Distillation
Answer:
Evaporation
Explanation:
because the ammonia is left unclosed
The smell of ammonia has been spread from a corner to entire room by the process of diffusion. Thus, option B is correct.
Ammonia has been the liquid compound with the formula [tex]\rm NH_4[/tex]. It has a pungent smell. Ammonia has been used in several synthesis reactions, and in various industrial processes.
The diffusion has been the process of transfer of molecules from higher concentration to lower concentration. The smell of ammonia has been spread in the entire laboratory from a corner.
The ammonia molecules in the bottle are at higher concentration while there has been lower concentration of ammonia in the environment. With the process of diffusion there has been the transfer of ammonia molecules in the environment.
Thus, diffusion has been responsible for spreading the smell of ammonia in the laboratory from a corner. Thus, option B is correct.
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a man is 72 inches tall, what is his height in meters? round to three significant figures.
Answer:
1.829 meters is the answer
Explanation:
How many moles of zinc are in 12.044 X 10^26 zinc atoms
Explanation:
Explanation:
The problem basically wants you to find a way to convert between the number of atoms present in the sample and the number of moles they are equivalent to.
To convert between atoms and moles we use something called Avogadro's constant, which basically acts as the definition of a mole.
More specifically, in order to have one mole of an element you need 6.022⋅1023 atoms of that element. You can thus use this number as a conversion factor to take you from atoms to moles or vice versa.
In your case, you will have
Do you know when the transfer of heat/thermal energy has ended
3. Two or more substances that are not
chemically combined...
Element
Mixture
Compound
Answer:
Its a mixture.
A student was performing a series of experiments to verify the density of a liquid. The table shows the results of four experiments. Which of these statements is correct?
Experiment No. Density (g/cc)
1 0.70
2 0.81
3 0.80
4 0.81
A) The mean of the data is 0.7.
B) The mean of the data is 0.8.
C) The median of the data is 0.70.
D) The median of the data is 0.81.
Answer:
0.8
Explanation:
since when you add them up you get 3.12 and divide it you get 0.78. Round and you will get 0.8
6) What types of atomic orbitals are in the third principal energy
level?
C A sand p only
B. p and d only
CC. s, p, and d only
CD. s.p. d, and f
Answer:
Types of atomic orbitals present in the third principal energy are s, p and d only .
Explanation:
OPTION A-: s and p atomic orbitals - these two orbitals are present in second principal energy level. Therefore , the option is incorrect. OPTION B-: p and d only - This option is wrong as there is no such principal level energy where , s atomic orbital is absent .OPTION C-: s , p and d only -these orbitals are present in third principal energy level. The third major level of energy has one orbital, three orbitals of p, and five orbitals of d, each of which can contain up to 10 electrons. The third stage thus holds a maximum of 18 electrons. This option is correct .OPTION D-: s , p, d and f only -There is also a f sublevel at the fourth and higher stages, containing seven f orbitals, which can accommodate up to 14 electrons at most. Therefore, up to 32 electrons will hold the fourth level: 2 in the s orbital, 6 in the three p orbitals, 10 in the five d orbitals, and 14 in the seven f orbitals. This option is incorrect .Thus , the correct option is C (s , p and d only .)
Answer:
s, p, and d
Explanation:
The people on this website are the only reason I'm passing!
N e ways, help?
A sample of oxygen gas at STP is depicted in the diagram in the picture (4) of the image attached.
What is an oxygen molecule?An oxygen molecule is a diatomic molecule, which is a molecule made up of just two atoms of the same element. The oxygen molecule in this instance is made up of two oxygen atoms.
If you have a lot of oxygen atoms at STP, they will spontaneously combine to produce O₂ because double bonds between oxygen atoms make their structure more stable.
If we carefully examine the figure in the attached image, we will see that it depicts a molecule made up of two atoms of the same element, which perfectly matches the definition of the oxygen molecule.
Therefore, this is shown in diagram (4), spontaneously combine to produce O₂ because double bonds between oxygen atoms make their structure more stable.
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How many electrons do carbon and oxygen share?
I-0-I
:0:
Intro
Done
oxygen has 6 valence electrons and 2 electrons and carbon has 4 electron
Answer:
4!!!!!!!!!!
Explanation:
i got it right
What should you wear during lab investigations to protect your eyes?
Answer:
goggles
Explanation:
Which element has a greater atomic radius? Fluorine or Potassium
Answer:
An atom is a basic unit of a chemical element, such as hydrogen, helium ... a fluorine atom since the three additional protons the fluorine has will pull its ... As an example, potassium (K) has a larger average atomic radius (
The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate,
Answer:the atoms of a solid aluminium can are close together vibrating in a rigid structure if the can is warmed up on a hot plate
Explanation:
A chemical reaction takes place to allow instant cold packs to absorb energy. This is an example of a(n) __________.
A. physical change
B. exothermic reaction
C. endothermic reaction
D. precipitate
Answer:
c. Endothermic
Explanation:
endothermic reactions absorb heat, exothermic reactions release heat.
Could someone please tell show me steps to solve this, I am so confused.
9.80 grams of magnesium metal react with excess hydrochloric acid, and 29.8 grams of magnesium chloride are produced
by the reaction. What is the percent yield of this reaction?
Mg + HCI –> MgCl2 + H2
And this is y I should of paid attention in that one science class in middle school that taught this...
(￣▽￣;)
how many significant figures in 368.1371 ?
Which describes any compound that has at least one element from group 17?
Please answer correctly..
will give the brainliest!
Urgent!!!!!!
State two function of blood in our
body?
Answer:
transporting oxygen and nutrients to the lungs and tissues
forming blood clots to prevent excess blood loss
carrying cells and antibodies that fight infection
Explanation:
.......(◍•ᴗ•◍).......
5. Why does saliva production in the mouth decrease demineralization?
period 6, group 12 (2B)
Answer:
mercury or Hg
Explanation:
i looked at the periodic table haha
hope this helps and is right <3
What directions do periods go on a periodic table
Answer:
left to right
The periods go on a periodic table, left to right. The periodic table is the systematic arrangement of elements in row and column.
What is a periodic table ?The chemical elements are arranged in rows and columns in the periodic table, sometimes referred to as the periodic table of the elements. It is often used in physics, chemistry, and other disciplines, and is frequently regarded as a symbol of chemistry.
Because of the orderly arrangement of the elements, it is known as the periodic table. Periods refers to the horizontal rows, and Groups to the vertical columns.
The most significant role of hydrogen in the human body is to maintain your level of hydration, making it the most significant element on the periodic table.
All known elements are grouped together in the periodic table of elements into groups with related characteristics. It becomes a crucial tool for chemists, nanotechnologies, and other scientists as a result. You can forecast how chemicals will behave if you learn to utilize and comprehend the periodic table.
Thus, The periods go on a periodic table, left to right.
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In an ionic compound, the size of the ions affects the internuclear distance (the distance between the centers of adjacent ions), which affects lattice energy (a measure of the attractive force holding those ions together). Based on ion sizes, arrange these compounds by their expected lattice energy. Note that many sources define lattice energies as negative values. Please arrange by magnitude and ignore the sign. ∣∣lattice energy∣∣=absolute value of the lattice energy Na2S, K2S Cs2S Li2S
Answer:
Li2S> Na2S> K2S> CsS
Explanation:
The lattice energy of ionic species depends on the relative sizes of ions in the ionic compounds. As the size of ions increases, the lattice energy decreases and vice versa.
When the size of the anions are the same, the lattice energy now depends on the relative sizes of the cations. Therefore, since all the compounds are sulphides and the order of magnitude of ionic sizes is: Li^+ < Na^+ < K^+ < Cs^+.
Therefore, the order of decrease in lattice energy is; Li2S> Na2S> K2S> CsS
Plz help! The best answer will be marked as brainliest!
Make a funny sentence for flammability and compounds for Magnesium
Here is an example for Mercury, it HAS to for Magnesium
“I love to travel but I do corrode aluminum so we won’t be flying off on adventures in airplanes planes anytime soon”
Answer:
I literally just answered this question
Explanation:
Give me a brainliest
What changes in trade did Europeans hope to bring about by finding sea routes to Asian markets?
PLEASE ANSWER THIS WUICK PLEASEEEE
Answer:
controlled by the Arabs, who brought frankincense and myrrh by camel caravan from South Arabia.
Suppose 50.0 grams of compound AB reacts completely with 100.0 grams of compound CD, how many grams of products will be formed, according to the Law of Conservation of Matter?
a. 50
b. 100
c. 150
d. 200
Answer:
Option C = 150
Explanation:
First of all we will understand what is law of conservation of mass.
Law of conservation of mass:
This law stated that, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six number of carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of chemical equation so this reaction followed the law of conservation of mass because mases are same on both side.
In given chemical reaction:
AB + CD → X
50 g + 100 g = 150 g
Thus option c is correct.
How many protons, neutrons, and electrons does the atom above have?
-12 protons, 7 neutrons, 1 electron
-7 protons, 12 neutrons, 1 electron
-12 protons, 5 neutrons, 7 electrons
-7 protons, 5 neutrons, 8 electrons
-7 protons, 5 neutrons, 1 electron
-7 protons, 12 neutrons, 8 electrons
-5 protons, 7 neutrons, 8 electrons
Answer:
Nitrogen has 7 protons, 7 neutrons, and 7 electrons.
So, I'm not entirely sure about the choices you provided :)
When liquid water boils the distance between the particles increases
Answer:
If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid.
The distance between the particles increases tremendously the attraction doesn't change.
What occurs to the water particles whilst water boils?
Whilst water is boiled, the heat energy is transferred to the molecules of water, which begin to pass extra quickly. ultimately, the molecules have an excessive amount of power to stay connected as a liquid. while this takes place, they shape gaseous molecules of water vapor, which go with the flow to the floor as bubbles and tour into the air.
Does the space among particles increase when heated?On heating, their kinetic electricity pushes neighboring atoms or molecules other than each different. This pushing of atoms or molecules outcomes in a slightly accelerated distance among molecules and the volume of stable additionally increases.
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Compound Lattice Energy (kJ/mol) Compound Lattice Energy (kJ/mol) LiF 1030 NaCl 788 LiCl 834 MgCl2 2326 LiI 730 AlCl3 5376 Lattice Energy 1 Lattice Energy 2 For the lattice energies given above … in Lattice Energy 1, explain why LiF has a greater lattice energy than LiI in Lattice Energy 2, explain why NaCl has a smaller lattice energy than AlCl3
Answer:
The lattice energy decreases down the group and increases across the period, therefore, the lattice energy of LiF > lattice energy of LiI, and the lattice energy of NaCl < the lattice energy of AlCl₃
Explanation:
The given parameters are;
Compound [tex]{}[/tex] Lattice Energy (kJ/mol)
LiF [tex]{}[/tex] 1030
NaCl [tex]{}[/tex] 788
MgCl₂ [tex]{}[/tex] 2326
LiI [tex]{}[/tex] 730
AlCl₃ [tex]{}[/tex] 5376
Lattice is the energy that must be added in order to split one mole of a ionic solid compound into gaseous ions
Given that the force of attraction between charges is inversely proportional to the square of the distance separating the charges, we have that as the atomic radius increases progressively down the group, the lattice energy decreases, therefore, LiF which has a shorter inter nuclear distance than LiI due to fluorine, F, being higher up on the periodic table than iodine, I, has a greater lattice energy than LiI
Similarly, given that the atomic radius decreases across the period, and that sodium, Na, comes before aluminum, Al, as we move across period 3, of the periodic table, the inter nuclear distance between atoms of in NaCl is larger than the internuclear distances between the atoms of AlCl₃, as well as the presence of more chlorine atoms in AlCl₃ than in NaCl, the lattice energy of NaCl is smaller than the lattice energy of AlCl₃.