Answer:
Possibly a bad reaction as some people's immune systems are weaker than others
Explanation:
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
The picture provided shows the arrangement of electrons in atomic shells around the nucleus of four different elements.
Which statement is true about these elements?
A) All elements belong to the same period.
B) All elements belong to the same group.
C) Elements 1 and 4 belong to the same group.
D) Elements 2 and 3 belong to the same period.
Both element 1 and element 4 have one electron in their valence shell Therefore, they belong to the same group. Therefore, option (C) is correct.
Why do elements of the same group have similar chemical behavior?The chemical behavior of elements will depend on the number of electrons in their outermost shell. Elements that are placed in the same group have the same number of valence electrons. Therefore, elements present in the same group of the modern periodic table have similar chemical properties.
The elements with a similar outer shell electronic configuration in their atoms are organized in the same group of the modern periodic table. These valence electrons of an element are responsible their chemical properties and reactivities of the elements.
Elements 1 and 4 have one electron in their valence shell so they belong to the same group while elements 2 and 4 have two electrons in their valence shell that also belong to the same group.
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I've decided that i still want to have some orange juice
Answer:
Oh thats great..
But I hate juice :(
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.
pls asap figure it out pls I will mark brainliest
Answer:
NaCl (Na is a metal and Cl is a nonmetal) MgO (Mg is a metal and O is a nonmetal) Al2O3, NaF, Na2O
Explanation:
You have to have a metal and a non metal together for it to be ionic
What is the name of the compound NS2
Answer:
I believe what your looking for is Nitrogen disulfide
Explanation:
Hope this helps (:
Question
Your boss is required to provide job safety training:
A) only if you request the training
B) as soon as there are a sufficient number of new employees
C) before you start your job
D) within the first year of your new job
Answer:
C) before you start your job
Explanation:
its the 1st thing to do when ur on a job...i guess not sure but try it anyway....but if im wrong blame
Answer:
I think it's c (before you start your job)
Explanation:
cuz we can get experienced after we are provided job safety training and it is also the first thing we will be given.
sorry if I'm wrong
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:
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.
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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 .
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]
What is an example of an initiation phase for an addition
polymerization reaction?
SELECT AN ANSWER
H-O* + CH3-CH3 ----> H-O-CH2-CH2*
H-O* + CH3-CH3 ----> H-O-CH2-CH2-O-H
H-O* + CH2=CH * ----> CH3CH2*
H-O* + CH2=CH2 ----> H-O-CH2-CH2*
Answer:
H-O* + CH3-CH3 ----> H-O-CH2-CH2*
H-O* + CH[tex]_3[/tex]-CH[tex]_3[/tex] → H-O-CH[tex]_2[/tex]-CH[tex]_2[/tex]* is an example of an initiation phase for an addition polymerization reaction. Therefore, the correct option is option A.
What is polymerization reaction?High-molecular-weight compounds known as polymers are created by the aggregation of several smaller molecules known as monomers. Polymers make up the natural and manmade fibres used in clothes as well as the polymers that have revolutionised society.
Two fundamental methods for creating polymers exist: (a) joining small molecules together by an addition reaction, and (b) joining molecules while getting rid of a stable small molecule like water. Condensation processes, which combine addition and elimination reactions, are what this later type of polymerization is known as. H-O* + CH[tex]_3[/tex]-CH[tex]_3[/tex] → H-O-CH[tex]_2[/tex]-CH[tex]_2[/tex]* is an example of an initiation phase for an addition polymerization reaction.
Therefore, the correct option is option A.
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What does the nucleus of an atom do to its own electrons? To the electrons of a nearby atom?
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 percent composition of Phosphorus in Li3PO3
Answer:
you will get 17.983 g of lithium for every 100 g of lithium phosphate.
Explanation:
69.7% is the percent by mass of Lithium in Li[tex]_3[/tex]PO[tex]_3[/tex]. A percent is obtained by multiplying the result by 100.
One approach to show the concentration for an element within a compound or component in a combination is as a mass percentage. The mass percentage is computed by dividing the total weight of the combination by the mass of each component and multiplying the result by 100%. The mass percent is calculated by dividing the mass that contains the compound and solute by the mass for the element or solute.
99.795g/mol = molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex]
6.94g/mol = molar mass of Li
mass percentage of Li=(molar mass of Li/molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex])× 100
=(6.94/99.7)× 100
=69.7%
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What is a photon???????????
A photon is a fundamental particle of light that carries energy and behaves both as a particle and a wave.
It carries electromagnetic waves like visible light, radio waves, X-rays, and gamma rays. Photons have energy, momentum, and angular momentum but no mass.
Photons are particles and waves in quantum physics. They absorb, emit, and scatter stuff at the speed of light in a vacuum. Photons excite electrons in atoms and molecules, starting physical and chemical reactions.
E = hf, where E is the photon's energy, h is Planck's constant, and f is its frequency. Quantum physics relies on photons to comprehend light and matter interactions.
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Which safety procedure could prevent an accident?
using a fire extinguisher
using glass without chips or cracks
smelling a mixture of chemicals
getting a bandage out of the first aid kit when bleeding
Answer:
B
Explanation:
In Step 5, you will calculate H+/OH– ratios for more extreme pH solutions. Find the concentration of H+ ions to OH– ions listed in Table B of your Student Guide for a solution at a pH = 2. Then divide the H+ concentration by the OH– concentration. Record these concentrations and ratio in Table C. What is the concentration of H+ ions at a pH = 2? mol/L What is the concentration of OH– ions at a pH = 2? mol/L What is the ratio of H+ ions to OH– ions at a pH = 2? : 1
The ratio of H⁺ ions to OH⁻ ions at a pH = 2 is 10¹⁰
Further explanationGiven
ph = 2
Required
The concentration of H⁺ and OH⁻ ions
Solution
The concentration of H⁺ ionspH=-log[H⁺]
2=-log[H⁺]
[H⁺]=10⁻²
The concentration of OH⁻ ionspH+pOH=14
pOH=14-2
pOH=12
pOH=-log[OH⁻]
12=-log[OH⁻]
[OH⁻]=10⁻¹²
The ratio of H⁺ ions to OH⁻ ions at a pH = 2[tex]\tt \dfrac{10^{-2}}{10^{-12}}=10^{10}[/tex]
Answer:
First one: 0.01
second one: 0.000000000001
third one: 10000000000
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 is gamma radiation produced?
Answer:
They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.
Why did workers form labor unions?
Answer:
Labor unions were created in order to help the workers with work-related difficulties such as low pay, unsafe or unsanitary working conditions, long hours, and other situations. ... Sometimes the unions organized strikes in order to try to change the conditions of the workers.
Explanation:
Answer:
to speak with one voice
Explanation:
a p e x
If a concentrated solution of acetic acid is 99.5 % HC2 H3 O2 and has a density of 1.05 g/mL, what is the concentration of this acid in moles per litre?
Answer:
[CH₃COOH] = 17.4 M
Explanation:
Acetic acid → CH₃COOH
Molar mass → 60 g/mol
99.5% is percent by mass concentration. It means that 99.5 grams of solute are contained in 100g of solution.
Density → 1.05 g/mL. This data is always referred to solution, not solute!.
We determine solution's volume:
1.05 g/mL = 100 g / V → V = 100 g /1.05 g/mL → 95.2 mL
Now we know, that 99.5 g of acetic acid are contained in 95.2 mL
Let's convert to mmoles → 99.5 g / 60 g/mol = 1.66 moles
We convert solution's volume to L → 95.2 mL . 1L / 1000 mL = 0.0952 L
M (mol/L) = 1.66 mol / 0.0952 L = 17.4 M
Horsetails are helpful for treating
bee stings.
fevers.
urinary tract infections.
bleeding injuries.
Answer:
urinary tract infections. B
Explanation:
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.
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.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
1 Aluminum reacts with oxygen to produce aluminum oxide, what is the chemical equation?
Answer: Aluminum reacts with oxygen to produce aluminum oxide as follows: 4Al + 3O2 → 2Al2O3 a.
Explanation: I really really hope that was helpful.
5. What charge does iron have in iron (111) oxide?
Answer:
0
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
PWEaseee help mweee ill mark brainliest I just need the answer pls and thank you amazing people