Answer:
10
Explanation:
how have scientists been able to determine the composition of earth's layers?
A. by looking at how X-rays affect the planet
B. by studying the magnetic fields of various planets and moons
C. by looking at how seismic waves change speeds as they travel through Earth
D. by studying layers of other planets and moons
Why is it important for scientists to review and repeat the work of other scientists
Answer:
Accuracy
Explanation:
It is important for scientists to review the work of other scientists, so they can be sure there are no mistakes or lack of judgement. They repeat to compare results to make hypotheses.
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
PLEASE HURRY
Which layer of Earth is the densest and why is that so?
A: The outer core is densest due to gravitational compression.
B: The outer core is densest due to generation of radiogenic heat.
C: The outer core is densest due to accretion.
C: The inner core is densest due to gravitational compression.
D: The inner core is densest due to generation of radiogenic heat.
Answer:
D
Explanation:
Answer: C: The inner core is densest due to gravitational compression
Explanation:
What is the reason you can smell food cooking even when you're not in
the kitchen?
A.
the particles spread from high concentration to low concentration
B.
the particles spread from low concentration to high concentration
C. the particles come together from high concentration to low concentration
D. the particles come together from low concentration to high concentration.
Answer:
the answer should be A
What is the name of the compound NS2
Answer:
I believe what your looking for is Nitrogen disulfide
Explanation:
Hope this helps (:
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:
What is the mass of a 270 cm3 sample of a metal with density of 3.66 g/cm3?
Answer:
988.2 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 3.66 × 270
We have the final answer as
988.2 gHope this helps you
What does the nucleus of an atom do to its own electrons? To the electrons of a nearby atom?
instructions for #4-5, balance each equation after substituting symbols and formulas for words, remembering to include abbreviations for the physical state.
For subscripts, just make sure the number is in the right location in the compound formula.
4. Iodine crystals react with chlorine gas to form solid iodine trichloride.
5. Solid sodium bicarbonate reacts with hydrochloric acid [HCl (aq)] to produce aqueous sodium chloride, water, and carbon dioxide gas.
Answer:
Ok:
Explanation:
4.
[tex]I_2_{(s)} + 3Cl_2_{(g)} => 2ICl_3{(s)}[/tex]
5.
[tex]NaHCO_3_{(s)} + HCl_{(aq)} => NaCl_{(aq)} + H_2O_{(l)} + CO_2_{(g)[/tex]
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.
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
3. Which of the following claims do NOT a limitation of Bohr's model? *
Electrons in an orbital have constant energy
Electrons can exist in between energy levels
Electrons must absorb a quantum to move up an energy level
Electrons behave like particles
Answer:
B. Electrons can exist in between energy levels .
Explanation:
The value of energy for each energy level in an atom is quantized. Thus, electrons are not allowed to be found in between the energy levels.
When an electron absorbs energy, it becomes excited. And it would jump to a higher energy level whose energy is equal to the new energy of the electron. If the value of its new energy is less than the energy of higher levels but greater than the energy of it current energy level, the electron remains in its initial level. This is because, electrons do not exist in between energy levels .
Predict the balanced product for the acid base reaction of phosphoric acid with ammonium hydroxide.
Answer:
htt ps://w ww.you tube. com/watch?v =oyy377 Yoj4I
Explanation:
What mass of potassium would react with excess chlorine to produce 156 g of potassium chloride?
____ K + ____ Cl2 ____ KCl
Answer:
Explanation:
Oxygen is prepared by catalytic decomposition of potassium chlorine (KClO3). Decomposition of potassium, chloride gives potassium chloride (KCl) and oxygen (O2). How many moles and how many grams of KClO3 are required to produce 2.4 mole O2?
Brooke decides to model a lunar eclipse. She attaches a large poster of the Sun to her wall to represent the Sun. She then decides that her head will represent Earth, and the direction she is facing will indicate the direction an observer on Earth is facing. She will then hold a small ball in her hand to represent the Moon. In order to model a person watching a lunar eclipse, Brooke faces the "Sun," stretches out her hand, and faces the "Moon" in front of her. What aspect of Brooke's model should be corrected?
A. Brooke should turn so that the Sun is on her right, and hold the Moon to her left.
B. Brooke should turn so that her back is to the Sun, and hold the Moon behind her.
C. Brooke should turn so that the Sun is on her left, and hold the Moon in front of her.
D. Brooke should turn so that her back is to the Sun, and hold the Moon in front of her.
PLEASE HELP ITS A TEST :(((
Answer:
its D
Explanation:
Brooke should turn so that her back is to the Sun to her wall, and hold the Moon (ball representing Moon) in front of her. Therefore, option (D) is correct.
What is a Lunar eclipse?The eclipse of the moon occurs when the earth comes in between the sun and the moon. The earth blocks the light coming from the sun from reaching the surface of the moon and casts its shadow on the moon.
A lunar eclipse occurs on a full moon day and can be observed up to 3 lunar eclipses per year. A lunar eclipse can be categorized depending on how the sun, the moon, and the earth line up.
A partial lunar eclipse is when only a part of the moon moves into the shadow's earth. A total lunar eclipse is when the earth crossed directly in front of the moon and casts its shadow.
If Brooke's head is earth then it will be in the center and her back will be towards to sun poster on the wall. So that the ball in her hand can play as a moon to show the lunar eclipse.
Learn more about the Lunar eclipse, here:
https://brainly.com/question/12075389
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An object spinning on its axis is called
The temperature of a city during a week was 35° C, 36°C, 34°C, 38°C, 40°C, 39°C and 44°C. What was the average daily temperature of the town for the week?
Answer:38°
Explanation:
PLEASE HELP ASAP Chet is creating a catapult that will allow him to propel a ball farther than he is capable of throwing it. As he is creating the device, he finds that that catapult launches the ball straight up into the air. The catapult should propel the ball up and forward to create a trajectory.
Which of the following is the best solution to this problem?
A.
leave the design as is because the ball goes higher than he can throw it
B.
make changes to the design to allow it to launch the ball a farther distance
C.
discard the device and begin the engineering process again from the start
D.
leave the design as is but perform more tests to see if the problem improves
Answer:
IM NOT COMPLETELY SURE BUT ITS ETHER A OR B IM SORRY ;//
Explanation:
Question 11 of 25
How do home computer scanners use electromagnetic waves?
A. The waves are absorbed or reflected to capture images or
information
B. The scanners change information received into modified radio
waves
C. The waves are absorbed by objects, making them warmer.
D. The waves make objects brighter, making them easier to see.
Ffff
Answer:
a.The waves are absorbed or reflected to capture images
Explanation:
How Things Work: TSA scanners use electromagnetic waves for detection. ... These waves are bounced off the body of the person being scanned to create a three-dimensional image on the computer. The backscatter units instead bounce low-level electromagnetic X-rays off the body to create an image on the computer
Answer:
A. The waves are absorbed or reflected to capture images or
information
Explanation:
How many moles are in 7.91 X 1022 atoms of He?
Answer:
amount of He = (7.91 × 10^22) ÷ (6.02 × 10^23) = 0.131mol (3sf)
Explanation:
you make use of the mole concept formula
amount(mol) = number of particles ÷ 6.02 × 10^23
(6.02 × 10^23 is the avogadro constant, which is an extremely important number in this formula for mole concept)
why is magneisum a metal
Answer:
Chemical element, metallic, symbol Mg, situated in group IIa in the periodic table, atomic number: 12, atomic weight: 24,312. ... Magnesium is known for a long time as the lighter structural metal in the industry, due to it's low weight and to it's capability of forming mechanically resistant alloys.
The prefix "semi-" means "partly". Based on your knowledge of the properties of elements, which kind of element is most likely used to make semiconductors?
liquids
metalloids
metals
nonmetals
Answer:
metalloids
Explanation:
The kind of element most likely used to make semiconductors are the metalloids.
These elements have properties between those of metals and non-metals in that they are not truly metals and are partly non-metals.
Under certain conditions they show features of metals or non - metals. The class of these elements are the metalloids. They are used to make semiconductors which are major components of electronics.What is “rounding up”?
It makes the number simpler by putting it up to the next ten ex. 37 will be rounded up to 40
Why is calcium carbonate preferred over lumps of calcium carbonate for synthesis of calcium chloride
Answer:
it reacts to limestone better and is a bit more firmer and mostly preferred over because of how fast it can react towards chemicals
The table provided shows the properties of four elements.
Based on this data, it is reasonable to conclude that which element is a metalloid?
A) 1
B) 2
C) 3
D) 4
Hi guys . I'm having some troubles with physics and chemistry .
Do you know any sites or apps that can help me with any topic in physics and chemistry ( apart from Khan academy ) ?
Note : The site or app has to be able to teach and explain topics in Physics and Chemistry .
Explanation:
byju's ig. Cause it gives a proper concept
ANSWER ASAP
1. NH₄NO₂(s) → N₂(g) + H₂O(l)
1a. Write the number (if any) that should go in front of NH₄NO₂(s), N₂(g), and H₂O(l) in order with commas in between. If there shouldn't be a number, write "no number".
1b. What type of reaction is represented in this equation?
2. Cl₂(g) + KBr(aq) → KCl (aq) + Br₂(l)
2a. Write the number (if any) that should go in front of each compound in order with commas in between. If there shouldn't be a number, write "no number".
2b. What type of reaction is represented in this equation?
3. FeS(s) + HCl(aq) → H₂S(g) + FeCl₂ (aq)
3a. Write the number (if any) that should go in front of each compound in order with commas in between. If there shouldn't be a number, write "no number".
3b. What type of reaction is represented in this equation?
Answer:
Ok:
Explanation:
1a: [tex](no number) NH_4NO_2_{(s)} => (no number) N_2_{(g)} + 2 H_2O_{(l)}[/tex]
1b: Decomposition reaction
2a. [tex](no number) Cl_2_{(g)} + 2 KBr_{(aq)} => 2 KCl_{(aq)} + (no number) Br_2_{(l)}[/tex]
2b Single replacement reaction
3a. [tex](no number)F_2S_{(s)} + 2HCl_{(aq)} =>(no number)H_2S{(g)} + (nonumber)FeCl_2_{(aq)}[/tex]
3b. Double replacement reaction
Fun fact! <3
An apple, potato, and onion all taste the same if you eat them with your nose plugged
Answer:
:O Fr? Bet let me go get them lol
✧ Yes, since one of our senses are missing we won't really detect the taste.
Explanation: Think about it, we usually smell food and we can already tell if it's going to taste good or not. Looking or touching food doesn't always help to know if we will like the taste. ✧
What volume of 0.100 M NaCl is needed to react completely with 5.00 mL of 0.200 M Pb(NO3)2?
Answer:
20 mL
Given data:
Molarity of NaCl = 0.100 M
Volume of Pb(NO₃)₂ = 5.00 mL (5.0/1000 = 0.005 L)
Molarity of Pb(NO₃)₂ = 0.200 M
Volume of NaCl needed = ?
Solution:
Chemical equation:
2NaCl + Pb(NO₃)₂ → PbCl₂ + 2NaNO₃
Number of moles of Pb(NO₃)₂:
Molarity = number of moles / volume in L
0.200 M = number of moles / 0.005 L
Number of moles = 0.200 M ×volume in L
Number of moles = 0.001 mol
now we will compare the moles of NaCl and Pb(NO₃)₂.
Pb(NO₃)₂ : NaCl
1 : 2
0.001 : 2/1×0.001 = 0.002 mol
Volume of NaCl:
Molarity = number of moles / volume in L
0.100 M = 0.002 mol / volume in L
Volume in L = 0.002 mol / 0.100 M
Volume in L = 0.02 L
volume in mL:
0.02 L × 1000 mL/1 L
20 mL