HELPPP NOW PLSSS IM GIVING 22 POINTS TO WHOEVER ANSWERS
Which is the control center for the endocrine system?
the thymus
the hypothalamus
the pancreas
the thyroid
Answer:
The hypothalams
Explanation:
It is the part of the brain that controls the endocrine system.
HOPE THIS HELPED
The hypothalams ~~~~~~
If you find a chemical in the lab and are unsure of
its identity, what is the best way to find out what it
is?
Answer:
C. read the label on the container
Explanation:
What information is found in an SDS? Check all that apply.
A. the identification of the chemical
C. the chemical and physical properties of the substance
D. the first-aid measures to take if an accident occurs involving the chemical
Answer:
C
Explanation:
just did it
Dinitrogen pentoxide is used in the preparation of explosives. If 7.93 mol of
dinitrogen pentoxide undergoes simple decomposition, what volume of Oz(9) is
produced at 48.0 °C and 125 kPa?
The volume of O₂ produced: 84.6 L
Further explanationGiven
7.93 mol of dinitrogen pentoxide
T = 48 + 273 = 321 K
P = 125 kPa = 1,23365 atm
Required
Volume of O₂
Solution
Decomposition reaction of dinitrogen pentoxide
2N₂O₅(g)→4NO₂(g)+O₂ (g)
From the equation, mol ratio N₂O₅ : O₂ = 2 : 1, so mol O₂ :
= 0.5 x mol N₂O₅
= 0.5 x 7.93
= 3.965 moles
The volume of O₂ :
[tex]\tt V=\dfrac{nRT}{P}\\\\V=\dfrac{3.965\times 0.082\times 321}{1.23365}\\\\V=84.6~L[/tex]
What is period? A group?
What can help overcome a positive enthalpy of solution and allow a solid
solute to dissolve in water?
A. A decrease in entropy
B. A large amount of energy released
C. A large amount of energy absorbed
D. An increase in entropy
Answer: D. An increase in entropy
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.
For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.
To overcome a positive enthalpy of solution and allow a solid solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.
how many moles of methane are in 7.31*10^25 molecules?
121 mol CH₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Organic
Writing chemical compoundsWriting organic structuresPrefixesAlkanes, Alkenes, AlkynesAtomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
7.31 × 10²⁵ molecules CH₄
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[tex]\displaystyle 7.31 \cdot 10^{25} \ molecules \ CH_4(\frac{1 \ mol \ CH_4}{6.022 \cdot 10^{23} \ molecules \ CH_4} ) = 121.388 \ mol \ CH_4[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
121.388 mol CH₄ ≈ 121 mol CH₄
CARDS
In a science experiment, Marisa concludes that no chemical reaction has occurred. What evidence would support
this conclusion?
A. the mass and total number of atoms were conserved
B. no energy were released
C. a new element was created
D. no new substance was formed
Answer:d
Explanation:
determine the theoretical yield.
aluminum metal reacts with aqueous nickel II sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. in this reaction 108 grams of aluminum were combined with 464 grams of nickel II sulfate to produce 274 grams of aluminum sulfate.
The question is incomplete, the complete question is;
In this stoichiometry problem, determine the percentage yield:
Excess aluminum metal reacts with aqueous nickel(II) sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. In this reaction 108 g of aluminum were combined with 464 g of nickel(II) sulfate to produce 274 g of aluminum sulfate.
Answer:
80%
Explanation:
The correct equation for this reaction is;
2Al(s) + 3NiSO4(aq) --------> Al2(SO4)3 + 3Ni(s)
We already know that Al is in excess then NiSO4 is the limiting reactant.
Hence, Number of moles in 464 g of NiSO4 = mass/ molar mass
Molar mass of NiSO4 = 155 g/mol
Number of moles = 464g/155g/mol = 2.99 moles
Number of moles of Al2(SO4)3 = mass/molar mass
molar mass = 342 g/mol
So, Number of moles = 274g/342g/mol = 0.8 moles
Given the stoichiometric reaction equation;
3 moles of NiSO4 yields 1 mole of Al2(SO4)3
2.99 moles of NiSO4 yields 2.99 * 1/3 = 1 mole of Al2(SO4)3
percentage yield is given by; actual yield/ theoretical yield * 100/1
actual yield = 0.8 moles of Al2(SO4)3
Theoretical yield = 1 mole of Al2(SO4)3
Hence;
% yield = 0.8/1 * 100 = 80%
define the following terms
A) chemical family
B) period
C) metalloid
Answer:
Chemical Family means a group of elements in the Periodic Table or, more commonly, compounds that share certain physical and chemical characteristics and have a common name.
A period in the periodic table is a row of chemical elements.
metalloid is an element (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid nonmetals or semiconductors.
DUE VERY VERY VERY SOON
What are the rows of elements called on the periodic table?
Answer:
"The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups."
Explanation:
I GIVE OUT FREE POINTS
4. Pb +FeSO, - PbSO, +Fe
Reaction Type:
Answer:Fe
Explanation:
Which type of climate does Florida have due to its latitude?
Explain in a short sentence how you can tell a reaction is a decomposition reaction.
Answer: A decomposition reaction occurs when one reactant breaks down into two or more products.
Mark me as brainilist pls
A woman has pain in her ovaries. In which
quadrants of her abdominopelvic cavity might she
be experiencing pain?
Check all that apply.
the right lower quadrant
the left lower quadrant
the left upper quadrant
the right upper
Answer:
The right lower quadrant
The left lower quadrant
Explanation:
Those quadrants contain the ovaries and I just got it correct on the assignment.
How many moles are in 43 grams of lithium (LI)?
Answer:
6.19507275608684
Explanation:
Can someone balance these equations?
This is mind numbing, but I got you.
3NaOH + 1FeCl3 = 1Fe(OH)3 + 3NaCl
3Mg + 2H3(PO)4 = 1Mg(PO4)2 + 3H2
an object moving with a speed of 5m/s has a kinetic energy of 100J what is the mass of the object
Answer:
k. e. = 1/2 mv^2
100 = 1/2 * m * 5^2
100 = 1/2 * m * 25
m = 100 *2/25
m = 8 kg
hope it helps you
which rock is the result of changes on the Earth's surface?
igneous rock
sedimentary rock
metamorphic rock
Answer:
metamorphic
Explanation:
when one rock changes another rock the rock that got changed is now metamorphic
State and explain each law of motion.
Answer:In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction
Explanation:
Answer:
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Explanation:
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5. CaCO, - CaO+CO,
Reaction Type
Answer:
(a) Decomposition: A substance breaks down to smaller species. [e.g. CaCO3(s) → CaO(s) + CO2(g) Decomposition of limestone to calcium oxide (quicklime) and carbon dioxide on heating.]
Give two limitations of law of Constant Composition
Answer:
1.The law does not hold true if the different isotopes of the element are involved in making chemical compound.
2.The law is not applicable when elements combine in the same ratio but different compounds are formed.
SOMEONE HELP PLEASE!
Answer:
The nose consists of the visible external nose and the internal nasal cavity. The nasal septum divides the nasal cavity into right and left sides. Air enters two openings, the external nares (nostrils; singular, naris), and passes into the vestibule and through passages called meatuses. The bony walls of the meatuses, called concha, are formed by facial bones (the inferior nasal concha and the ethmoid bone). From the meatuses, air then funnels into two (left and right) internal nares. Hair, mucus, blood capillaries, and cilia that line the nasal cavity filter, moisten, warm, and eliminate debris from the passing air.
The pharynx (throat) consists of the following three regions, listed in order through which incoming air passes:
The nasopharynx receives the incoming air from the two internal nares. The two auditory tubes that equalize air pressure in the middle ear also enter here. The pharyngeal tonsil (adenoid) lies at the back of the nasopharynx.
The oropharyrnx receives air from the nasopharynx and food from the oral cavity. The palatine and lingual tonsils are located here.
The laryngopharynx passes food to the esophagus and air to the larynx.
The larynx receives air from the laryngopharynx. It consists of several pieces of cartilage that are joined by membranes and ligaments, shown in Figure 2:
The epiglottis, the first piece of cartilage of the larynx, is a flexible flap that covers the glottis, the upper region of the larynx, during swallowing to prevent the entrance of food.
The thyroid cartilage protects the front of the larynx. A forward projection of this cartilage appears as the Adam's apple (anatomically known as the laryngeal prominence).
The paired arytenoid cartilages in the rear are horizontally attached to the thyroid cartilage in the front by folds of mucous membranes. The upper vestibular folds (false vocal cords) contain muscle fibers that bring the folds together and allow the breath to be held during periods of muscular pressure on the thoracic cavity (straining while defecating or lifting a heavy object, for example). The lower vocal folds (true vocal cords) contain elastic ligaments that vibrate when skeletal muscles move them into the path of outgoing air. Various sounds, including speech, are produced in this manner.
The cricoid cartilage, the paired cuneiform cartilages, and the paired corniculate cartilages are the remaining cartilages supporting the larynx.
The trachea (windpipe) is a flexible tube, 10 to 12 cm (4 inches) long and 2.5 cm (1 inch) in diameter (Figure 2).
The mucosa is the inner layer of the trachea. It contains mucus‐producing goblet cells and pseudostratified ciliated epithelium. The movement of the cilia sweeps debris away from the lungs toward the pharynx.
The submucosa is a layer of areolar connective tissue that surrounds the mucosa.
Hyaline cartilage forms 16 to 20 C‐shaped rings that wrap around the submucosa. The rigid rings prevent the trachea from collapsing during inspiration.
The adventitia is the outermost layer of the trachea. It consists of areolar connective tissue.
The primary bronchi are two tubes that branch from the trachea to the left and right lungs.
Inside the lungs, each primary bronchus divides repeatedly into branches of smaller diameters, forming secondary (lobar) bronchi, tertiary (segmental) bronchi, and numerous orders of bronchioles (1 mm or less in diameter), including terminal bronchioles (0.5 mm in diameter) and microscopic respiratory bronchioles. The wall of the primary bronchi is constructed like the trachea, but as the branches of the tree get smaller, the cartilaginous rings and the mucosa are replaced by smooth muscle.
Alveolar ducts are the final branches of the bronchial tree. Each alveolar duct has enlarged, bubblelike swellings along its length. Each swelling is called an alveolus. Some adjacent alveoli are connected by alveolar pores.
The respiratory membrane consists of the alveolar and capillary walls. Gas exchange occurs across this membrane. Characteristics of this membrane follow:
Type I cells are thin, squamous epithelial cells that constitute the primary cell type of the alveolar wall. Oxygen diffusion occurs across these cells.
Type II cells are cuboidal epithelial cells that are interspersed among the type I cells. Type II cells secrete pulmonary surfactant (a phospholipid bound to a protein) that reduces the surface tension of the moisture that covers the alveolar walls. A reduction in surface tension permits oxygen to diffuse more easily into the moisture. A lower surface tension also prevents the moisture on opposite walls of an alveolus or alveolar duct from cohering and causing the minute airway to collapse.
Alveolar macrophage cells (dust cells) wander among the other cells of the alveolar wall, removing debris and microorganisms.
What does the formula of an ionic compound tell you?
Answer:
The overall ionic formula for a compound must be electrically neutral, meaning it has no charge. When writing the formula for the ionic compound, the cation comes first, followed by the anion, both with numeric subscripts to indicate the number of atoms of each.
Explanation:
What happens to valence electrons in ionic bonding?
Answer:
they are either donated to or taken by another atom to achieve octet arrangement
Explanation:
for example Na+ and Cl- .. they both have one extra and one less electron .
so they donate and receive one electron to/from each other to achieve the octet arrangement ..
Please actually help me.
Thank you!
Answer:
I say 20 is ur best option
What happens to water when it freezes?
its mass increases
its mass decreases
its density increases
its density decreases
Explanation:
When an object undergoes a physical change (solid to liquid, decrease in temperature etc.), the mass of the object remains constant.
When water freezes, the water molecules vibrate closer to one another and there is less space between the molecules.
The same number of water molecules now occupy a smaller volume, therefore their density increases.
The correct answer is the 3rd option.
At the time when the water should be freezed so here the density should be decreased.
What is density?The density refers to the mass of the unit volume with respect to the material substance.
The formula for density should be d = M/v
So here d means the density
And, m means mass
V means the volume
So it should be expressed in units with respect to the units of grams per cubic centimeter.
Hence the last option is correct.
Learn more about water here: https://brainly.com/question/24720645
Sodium Chloride is an ionic compound. Its molar mass is 58.44g. One formula unit of NaCl consists of one____, whose chemical symbol is___ and one___whose chemical symbol is___. Please help me to fill in the gaps :)
Answer: One formula unit of NaCl consists of one cation, whose chemical symbol is [tex]Na^+[/tex] and one anion whose chemical symbol is [tex]Cl^-[/tex]
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The cation is formed by the metal sodium which forms [tex]Na^+[/tex] and the anion is formed by non metal chlorine which forms [tex]Cl^-[/tex].
For a formula unit of sodium chloride, the charges have to be balanced , thus the valencies of ions are exchanged and the neutral compound result. Thus
[tex]Na^+[/tex] and [tex]Cl^-[/tex] combine to form neutral [tex]NaCl[/tex]
Some fruits and vegetables are preserved by pickling them. Nandini got confused
with the various steps to be taken to preserve mangoes. Can you help her to
arrange them in the correct order?
1. Cut the mangoes into pieces.
2. Keep the pieces in the sun.
3. Add salt to the pieces.
4. Store it in a dry jar.
5. Wash and dry them
Answer:
ye
Explanation:
ye
Of the three types of plate boundaries, which type is most likely to be associated
with pulling or tension forces?
transform
convergent
divergent
You have about ______ liters of blood in your body.
A. picks up nutrients, water, and waste materials
B. pulmonary circulation
C. the lungs, where it picks up oxygen again
D. capillaries
E. 5
F. systemic circulation
Answer:
E
Explanation: