Answer:
Muscles move body parts by contracting and then relaxing. Muscles can pull bones, but they can't push them back to the original position. So they work in pairs of flexors and extensors. The flexor contracts to bend a limb at a joint.
Explanation:
Hope it helps
Members in band noticed that drums seemed to vibrate and play themselves during practice. Why? A. The music was played at an natural frequency of the drums B .The music was so loud it caused the drums to vibrate Help pls!
Answer:
The music was played at an natural frequency of the drums
Explanation:
The natural frequency of a body is the frequency when we notice that the system oscillates without any driving or damping force. This is also referred to as the normal mode of vibration because all parts of the system move sinusoidally at the same frequency.
So, when music is played at the natural frequency of the drums, the drums tends to vibrate without any driving force. We can now say that the drums are 'playing themselves'.
9) A cactus plant, a snake, and a hawk can be members of the same
A- community
B- kingdom
C- population
D- species
13) gene are part of a
a-cell wall
b-chromsome
c-hormone
D-vitamin
For a chemical change to happen what must atoms be
Answer:
In a chemical reaction, only the atoms present in the reactants can end up in the products. No new atoms are created, and no atoms are destroyed. In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
Who discovered electrons using Crookes tube?
a.) Democritus
b.) Ernest Rutherford
c.) Hantaro Nagaoka
d.) J. J. Thomson
e.) John Dalton
f.) Niels Bohr
Answer:
William Crookes????????????????
Help 15 points!!!
Complete the following combustion reaction.
Answer:
C₈H₁₈ + 25/2O₂ —> 8CO₂ + 9H₂O
2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O
Explanation:
The reaction above is simply termed combustion reaction in which an organic compound react with oxygen to produce carbon dioxide and water. Thus, we can obtain the balanced equation for the reaction reaction as follow:
C₈H₁₈ + O₂ —> CO₂ + H₂O
There are 8 atoms of C on the left side and 1 atom on the right side. It can be balance by writing 8 before CO₂ as shown below:
C₈H₁₈ + O₂ —> 8CO₂ + H₂O
There are 18 atoms of H on the left side and 2 atoms on the right side. It can be balance by writing 9 before H₂O as shown below:
C₈H₁₈ + O₂ —> 8CO₂ + 9H₂O
There are 2 atoms of O on the left side and a total of 25 atoms on the right side. It can be balance by writing 25/2 before O₂ as shown below:
C₈H₁₈ + 25/2O₂ —> 8CO₂ + 9H₂O
Thus, the equation is balanced!
The above equation can also be written as follow:
C₈H₁₈ + 25/2O₂ —> 8CO₂ + 9H₂O
Multiply through by 2
2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O
Air pressure is caused by: gas particles striking the walls of a container or an object. b. gas particles are taking a test gas particles reaching 0 degrees Kelvin d. Air pressure has nothing to do with gas.
Answer:
D
Explanation:
DESPERATE WILL GIVE BRAINLIST AND THANKS
Which phase of cell division is shown?
prophase
metaphase
anaphase
telophase
anaphase
or if not
telophase
What are the 4 chambers and what is the function of each?
Answer:
Where are these Chambers located ], there is hundreds of them in the world
While both comets and asteroids are found to orbit the sun in our solar system which system which choice correctly explain how they are different
Answer:
Comets are made of ice, dust, and rocky material. Asteroids are made of rock and metal material.
Explanation:
thats how they are different from each other
Isotopes are atoms of the same element that have the same chemical property but may not have the same physical properties A true B false
Answer:
false
Explanation:
Atoms of the same element that differ in their numbers of neutrons are called isotopes. Many isotopes occur naturally. ... Different isotopes of an element generally have the same physical and chemical properties because they have the same numbers of protons and elec
Answer:
False
Explanation:
It says that it may not have the same physical properties but it always have the same physical properties.
Good quality water is needed for a healthy life.
In the United Kingdom, obtaining safe water for drinking is as simple as turning on a tap. The water is made safe to drink by what and companies.
However, in many parts of Africa and Asia, water used for drinking is contaminated and untreated. It is estimated that 2.2 million people die each year as a result of drinking contaminated water.
Explain why water for drinking is filtered and then treated with chlorine.
Answer:
Simply cuz so u can drink It without bacteries chlorine also changes a bit taste depends on RM
!Do not use this answer for cheating, please only use my answers to check your own!
Before tap water was found, people would use rocks, gravel, and sometimes even thick cloth to filter water. If you do not filter water, there is a huge chance that bugs, bacteria, viruses, and other things may be entering your body. Today some houses still have the past was of filtering, with rocks and gravel. Except chlorine is used to kill any bacteria that was left over the rocks and gravel may of missed.
Can anyone help me with the final answers plzzzzz
I dont understand and know the anwser to this
A temperature increase causes the particles to what ??!
Which of the following substances would have the highest dispersion forces? Why?
Ne, FCI, N2H4 SO2, SO3, C20H42, MgO, Si, CsI, Sn, H2O, CCl4
Answer:
Si
Explanation:
Dispersion force or London force is the force of attraction between two atoms or molecules in a substance in solid , liquid and gas . In gas , this force is minimum and in solid this force is maximum . In solid this force is maximum in metals in which this force forms metallic bond .
Among the given substances , Si , Sn , MgO , C₂₀H₄₂ are solid , so dispersion force will be high in them .
Among all as mentioned above , Si will have highest dispersion force . It is due to four covalent bond that bind two atoms of Si in solid silicon . Its three dimensional crystal structure consist of silicon atoms , all bound by four covalent bonds .
What are columns on the periodic table called? What is the significance of the columns on the periodic table?
Answer:
The vertical columns of the periodic table are called groups, or families. The significance is elements with similar properties are placed in the same vertical columns. The horizontal rows of the periodic table are called periods. The significance is that properties vary from left to right along the rows.
Explanation:
We just did this in science
Answer:
columns in the periodic table are reffered to as "periods". periods represent elements with the same number of shells i.e all elements in period 1 have 1 shell (k shell) and vice versa.
What role does valence electrons play in reactivity for an element?
Explanation:
The valence electrons within an atom is the number of electrons in its outermost shell.
These electrons are used by an atom to react with one another. They determine the extent to which an atom is ready to combine either by losing, gaining or sharing these electrons.
Every atom desires to have a completely filled outermost shell. Only the elements in group 8 have a complete octet. The need to attain stability is driven by the number of electrons in their valence shell. Therefore, some atoms are very reactive. Those needing one electrons to complete their octet and also those that must lose one electron are very reactive.please help
if a molecule is polar, what is true about the distribution of its valence electrons
what type of bond( ionic or covalent) does silver and nobelium form?
A plane flies from NY to LA at a constant speed of 800 km/hr. How long will it take the plane to fly the 4200 km? 5
As the plane plane flies at a constant speed of 800 km/hr the plane will take 5 hours 25 minutes to fly distance of 4200 km.
What is speed?Speed is defined as the rate of change of distance with time. It has the dimension of distance by time. Thus, the SI unit of speed is given as the combination of the basic unit of distance and the basic unit of Time. Thus, the SI unit of speed is metre per second. In everyday life, kilometre per hour or in countries like US and UK miles per hour are used as the unit of speed.
The SI unit of speed can be derived from the formula of velocity. Basically, velocity is the vector equivalent of speed. Mathematically, velocity is given as the ratio of displacement to the time taken.So, 800 km is traveled in 1 hour so 4200 km will be traveled 4200/800=5.25 which is 5 hours and 25 minutes.
Thus, the plane will take 5 hours 25 minutes to fly distance of 4200 km.
Learn more about speed,here:
https://brainly.com/question/7359669
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1.5 moles of N2 gas = ______L of N2 gas at STP
Answer:
33.6 lliter
Explanation:
volume in stp = no of moles *22.4
=22.4* 1.5=33.6liter
What is the Molar Mass of Cl4
Answer:473.39626 g/mol
Explanation:
Answer:
153.82 g/mol
Explanation:
what is the definition of base
Using the equation above, how many moles of Na are produced when 2.75 moles of H2 react with excess NaCl? will give BRAINLIEST
Answer:
5.5 moles of sodium are produced
Explanation:
Given data:
Number of moles of hydrogen = 2.75 mol
Number of moles of Na produced = ?
Solution:
Chemical equation:
H₂ + 2NaCl → 2HCl + 2Na
Now we will compare the moles of hydrogen and sodium from balance chemical equation:
H₂ : Na
1 : 2
2.75 : 2/1×2.75 = 5.5 mol
Thus, 5.5 moles of sodium are produced.
A solution of nitric acid is formed by dissolving 5.00grams of nitric acid in enough water to make 1.5 liters of solution.
c. What was the molarity of this solution?
d. What is the pH of this solution?
Molarity = 0.053 M
pH = 1.276
Further explanationGiven
5 g of HNO₃
1.5 L solution
Required
Molarity
pH
Solution
Molarity shows the number of moles of solute in every 1 liter of solution.
mol HNO₃(MW=63 g/mol) :
= mass : MW
= 5 g : 63 g/mol
= 0.079
Molarity :
=0.079 : 1.5 L
= 0.053 M
pH = -log [H⁺]
For strong acids like HNO₃ :
[H⁺] = a.M
a = valence of acid / amount of H⁺ released
M = acid concentration.
HNO₃ ⇒ H⁺ + NO₃⁻⇒ valence 1(amount of H⁺=1)
[H⁺]=1 x 0.053
[H⁺]= 0.053 M
pH= - log 5.3 x 10⁻²
pH = 2 - log 5.3
pH= 1.276
A white solid was left out after a class had tidied up their
experiment. During the experiment, one of the pupils had
removed the label on the white solid. The teacher knew the
solid was a Group 1 metal halide, so they performed a
flame test followed by a silver nitrate test. The flame test
gave a red flame, and the silver nitrate test gave a cream
precipitate. What is the white solid?
Answer:
LiBr
Explanation:
Group 1 metals give a characteristic colour when subjected to flame test. The colour can tell us exactly what the identity of metal being studied.
Now, Lithium metal gives a red flame. Hence the group 1 metal ion is Li^+. Similarly, bromides give a creamy precipitate when reacted with silver nitrate.
This means that the solid substance under study is LiBr.
How do chemists use systems and order in their work?
Answer:
5 point) Chemists used systems and order because they study the basic unit of all forms of matter, which is the atom . However, there are several different kinds of atoms, called elements . Chemists organize these elements using the periodic table .
Explanation:
Help! I need to turn this in ASAP.
Answer: Potassium, Carbon and Oxygen, third option.
Explanation: K= Potassium, C= Carbon, O=Oxygen
In the sixteenth century, the geocentric theory was a daim with substantial evidence. Which of the following best describes why scientists began to regard the heliocentric theory as more acceptable?
Answer:
The heliocentric theory was better supported by data explaining the rotation of the planets and other bodies in the solar system.
Explanation:
What is a reaction rate?
Answer:
Reaction rate, in chemistry, the speed at which a chemical reaction proceeds. It is often expressed in terms of either the concentration (amount per unit volume)
Explanation:
Answer:
A measure of how fast products are made in a reaction.
Explanation:
i just took the test and it gave me this cuz the other person was wrong
