How did the development of the earliest idea about atoms differ from the later work of scientists?
It was based on sound evidence.
There were explanations for the idea.
It was based on the thoughts of an early philosopher.
There were experiments conducted to support the idea.
Answer:
C. It was based on the thoughts of an early philosopher.
Which term describes matter that can vary in composition?
Answer:
A mixture is matter that can vary in composition. ... A heterogeneous mixture is a type of mixture in which the individual substances are not evenly mixed. Because the substances in a heterogeneous mixture are not evenly mixed, two samples of the same mixture can have different amounts of the substance.
Explanation:
Classify each of the following as a Strong acid (sa) or a Weak acid (wa) and indicate how each should be written in aqueous solution.
1. hydrobromic acid
2. hydrochloric acid
3. carbonic acid
Write a net ionic equation for the reaction that occurs when aqueous solutions of hydrochloric acid and barium hydroxide are combined.
Answer:
A. 1. Strong acid (sa): Hydrobromic acid: HBr (aq)
2. Strong acid (sa); Hydrochloric acid: HCl (aq)
3. Weak acid (wa); Carbonic acid: H₂CO₃ (aq)
B. H+ (aq) + OH- (aq) ----> H₂O (l)
Explanation:
Strong acids are which ionize completely in aqueous solution into hydrogen ions and the corresponding anion. Examples of strong acids include hydrobromic acid, hydrochloric acid, tetraoxosulfate (vi) acid.
The ionization of hdyrobromic and hydrochloric acids in aqueous solution is given below:
1. Hydrobromic acid: HBr (aq) ----> H+ (aq) + Br- (aq)
Hydrobromic acid in aqueous solution ionizes completely into hydrogen ions and bromide ions
2. Hydrochloric acid: HCl (aq) ----> H+ (aq) + Cl- (aq)
Hydrochloric acid in aqueous solution ionizes completely into hydrogen ions and chloride ions
Weak acids are acids which ionizes only partially in aqueous solutions to hydrogen ions and the corresponding anions. Examples of weak acids are carbonic acid and ethanoic acid. The ionization of carbonic acid in aqueous solution is shown below:
3. Carbonic acid: H₂CO₃ (aq) ⇄ 2 H+ (aq) + CO₃²- (aq)
Carbonic acid ionizes partially only to give hydrogen ions and trioxocarbonate (iv) ions. The unionized acid exists in equilibrium with the ions produced by the partial ionization of the acid.
Part B:
The reaction between hydrochloric acid and barium hydroxide is a neutralization reaction producing barium chloride salt and water.
The net ionic equation of the neutralization reaction is given below :
H+ (aq) + OH- (aq) ----> H₂O (l)
Completa las siguientes reacciones, nombrando todos los compuestos que intervienen:
a) CH2=CH2 + energía
b) CH2=CH2 + H2O
c) CH2=CH2 + HCl
d) CH2=CH2 + Cl2
e) CH2=CH2 + H2
2 Completa las siguientes reacciones, nombrando todos los compuestos que intervienen:
a) CH4 + Cl2
b) CH2=CH2 + H2O
c) CH≡CH + H2
d) CH3-COOH + KOH
e) CH3OH + CH3-COOH
3 Completa y ajusta la siguientes reacciones nombrando todos los compuestos que intervienen en cada una de ellas:
a) CH3-COOH + NaOH
b) CH3-CH2I + NH3
c) CH2=CH2 + H2O
d) CH3-CH=CH2 + Br2
Answer:
1
Explanation:
hhihh2
Chromium (VI) forms two different oxyanions, the orange dichromate ion, Cr2o72-, And the yellow chromate ion, CrO4 2-. The equilibrium reaction between the ions is:
Cr2O7 2- (aq) + H2O(l)→ 2CrO4 2-(aq) + 2H(aq)
Explain
a) Why does the orange dichromate solution turn yellow when sodium hydroxide is added. Write the net ionic equation for this shift.
b) How will this system shift at equilibrium if the temperature is increased
Answer:
See explanation
Explanation:
Let us look at the reaction again;
Cr2O7 2- (aq) + H2O(l)⇄ 2CrO4 2-(aq) + 2H^+(aq)
When we add sodium hydroxide to the system as shown, the hydroxide ion removes the hydrogen ion thereby leaving a large concentration CrO4^2-(aq) in the system this causes the solution to turn green(equilibrium position shifts to the right).
The net ionic equation is;
OH^-(aq) + H^+(aq) ----> H2O(l)
The reaction;
OH^-(aq) + H^+(aq) ----> H2O(l) is exothermic hence, if the temperature of the system is increased, the equilibrium position will shift towards the left hand side and the solution turns orange.
Almost 99% of Earth's atmosphere is made up of two gases. What are the two gases and the percents of each?
A)
21% oxygen and 78% nitrogen
B)
21% water vapor and 78% oxygen
09
21% nitrogen and 78% oxygen
D)
21% carbon dioxide and 78% oxygen
Naturally occurring gallium is a mixture of isotopes
that contains 90.11% of Ga-69 (atomic mass = 68.93
u) and 9.89% of Ga-71 (atomic mass 70.92 u).
What is the average atomic mass of naturally
occurring gallium?
A) 69.93 amu
C) 69.50 amu
B) 69.12 amu
D) 69.00 amu
What word means the same as Chordata?
A. non-vertebrate
B. vertebrate
What is the pH of a solution whose hydronium ion [H20+] (or proton [H+1)
concentration is 7.6' 10-5 M?
Answer:
[tex]pH = - log(7.6 \times {10}^{ - 5} ) \\ pH = 4.12[/tex]
How many grams of hydrogen gas, H, are necessary to produce 119.0 g of ammonia, NH3?
Answer:
What's the equation?
Answer:
14.5 g
Explanation:
its true
True or False: Photosynthesis can take place under water.
True
False
Answer:
True
Explanation:
hope this helps mate
Write the equation showing the formation of a monosubstituted product when butane reacts with chlorine. Use molecular formulas for the organic compounds (C before H, halogen last) and the smallest possible integer coefficients.
Answer:
CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl
Explanation:
Alkanes react with halogens in the presence of light to yield alkyl halides. The degree of substitution increases as the reaction progresses. The reaction occurs by free radical mechanism.
The reaction between butane and chlorine molecule to yields a monosubstitution product occurs as follows;
CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl
Before the lab student needs to make necessary chemical reagent solutions, the teacher asked them to make 50.0mL of 1.0 M H2SO4 from a 6.0 M sock
V1=
M1=
V2=
M2=
Answer:
V1 = 8.3 mL
Explanation:
Step 1: Given data
Initial volume (V1): ?
Initial concentration (M1): 6.0 M
Final volume (V2): 50.0 mL
Final concentration (M2): 1.0 M
Step 2: Calculate the volume of the initial solution
We want to prepare a dilute solution from a concentrated one. We can calculate the volume of the initial solution using the dilution rule.
M1 × V1 = M2 × V2
V1 = M2 × V2 / M1
V1 = 1.0 M × 50.0 mL / 6.0 M = 8.3 mL
We will take 8.3 mL of the 6.0 M solution and add water until we have 50.0 mL.
What is the mass of 8.12 ×10^23
Answer:
59.3g
Explanation:
Mole = no. Molecules/6.02×10^23
Mole = (8.12×10^23)/(6.02×10^23)
Mole = 1.35mole
Molar mass of CO2 = 12+ 2(16)
Molar mass= 12 + 32= 44g/mol
Mole = mass/molar mass
Mass = Mole × molar mass
Mass = 1.35× 44
Mass= 59.35g
which of the following experiments raises ethical concerns
Answer:
Research that releases a poisonous gas into the air.
Explanation:
Since I don't know the options I will guess it is ^
You are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the ee of this solution
Answer:
ee = 96%
Explanation:
Enantiomeric excess, ee, is a way to express a mixture that is not enantiomerically pure. It is defined as 100 times the ratio between the differences of amounts of enantiomers and the total amunt. that is:
ee = |A-B|/ A+B * 100
ee = |98%-2%| / 98+2 * 100
ee = 96%The mass percent of element X
in X(NO3)2 is 52.55%.
Chemical analysis of a pure
sample of X(NO3)2 shows that
it contains 67.50 g of element
X. What is the total mass of
the pure sample?
Answer:
128.4 g
Explanation:
Step 1: Given data
Mass percent of element X in X(NO₃)₂: 52.55%Mass of the element X in the sample: 67.50 gStep 2: Determine the total mass of the sample
The mass percent of element X in X(NO₃)₂ is 52.55%, that is, there are 52.55 g of X every 100 g of X(NO₃)₂. Then, the mass of X(NO₃)₂ that contains 67.50 g of X is:
67.50 g X × 100 g X(NO₃)₂/52.55 g X = 128.4 g X(NO₃)₂
Which of the following is formed last in daughter cells when plant cells divide?
The nucleus
The nuclear envelope
The cell membrane
The cell wall
Answer:
The Cell Wall
Explanation:
How many moles of fluorine are in 100.0 g
The chemical formula for an emerald is Be3Al2(SiO3)6. An emerald can be described as
Answer:
Emerald is a compound made of Beryllium, Aluminium, Silicon and Oxygen with the formula, Be3Al2(SiO3)6
Explanation:
Answer:
A pure substance because its a compound
Explanation:
Balance the following equation and list the coefficients in order from left to right.
SF4 + __ H2O → _H2SO3 + HE
Vascular tissue
From Wikipedia, the free encyclopedia
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Cross section of celery stalk, showing vascular bundles, which include both phloem and xylem.
Detail of the vasculature of a bramble leaf.
Translocation in vascular plants
This article is about vascular tissue in plants. For transportation in animals, see Circulatory system.
Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant.
The cells in vascular tissue are typically long and slender. Since the xylem and phloem function in the conduction of water, minerals, and nutrients throughout the plant, it is not surprising that their form should be similar to pipes. The individual cells of phloem are connected end-to-end, just as the sections of a pipe might be. As the plant grows, new vascular tissue differentiates in the growing tips of the plant. The new tissue is aligned with existing vascular tissue, maintaining its connection throughout the plant. The vascular tissue in plants is arranged in long, discrete strands called vascular bundles. These bundles include both xylem and phloem, as well as supporting and protective cells. In stems and roots, the xylem typically lies closer to the interior of the stem with phloem towards the exterior of the stem. In the stems of some Asterales dicots, there may be phloem located inwardly from the xylem as well.
Between the xylem and phloem is a meristem called the vascular cambium. This tissue divides off cells that will become additional xylem and phloem. This growth increases the girth of the plant, rather than it
Given the Vapour Density of a hydrocarbon is 150, what is it's molecular formula.
Verdadero o falso si un átomo presenta de 5 a 7 electrones en su nivel más extremo tenderá a perderlos?
In the electrolysis of water, how long will it take to produce 75.00 L of H2 at 1.0 atm and 273 K using an electrolytic cell through which the current is 205.0 mA
answer is 2546 h
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An ion has 38 protons, 36 electrons, and 40 neutrons, what us the elements symbol
The symbol of the element in which it's ion has 38 protons, 36 electrons, and 40 neutrons is ⁷⁸₃₈Sr
How do I determine the symbol of the element?To obtain the symbol of the element, we shall obtain the mass number of the element. This is shown below:
Proton = 38Neutron = 40Mass number = ?Mass number = Proton + Neutron
Mass number = 38 + 40
Mass number = 78
Finally, we shall determine the symbol of the element. Details below:
Proton = 38Atomic number (z) = Proton = 38Mass number (A) = 78Symol of element =?From the periodic table, the element with atomic number of 38 is Strontium.
Thus, the symbol of the element will be ⁷⁸₃₈Sr
Learn more about symbol:
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How many molecules are there in 4.27 mol of tungsten(VI) oxide, WO3
Answer:
Molar mass of WO3 = 231.8382 g/mol Convert grams Tungsten(VI) Oxide to moles or moles Tungsten(VI) Oxide to grams Molecular weight calculation: 183.84 + 15.9994*3Explanation:
#hopeithelpsbrainliest me later.25.71 × 10²³ molecules are there in 4.27 mol of tungsten (VI) oxide, [tex]WO_3[/tex].
How to find the number of molecules ?To find the Number of molecules of substance multiply the number of moles of given substance by Avogadro number
Number of molecules = Number of moles × Avogadro's Number
Avogadro's NumberAvogadro's number [tex](N_{A})[/tex] is the number of particles in one mole of substance. 6.023 × 10²³ is known as Avogadro's constant / Avogadro's number.
Avogadro's number = 6.023 × 10²³ [tex]mol^{-}[/tex]
Now,
Number of molecules in 4.27 moles of [tex]WO_{3}[/tex]
= Number of moles of [tex]WO_{3}[/tex] × Avogadro's Number
= 4.27 × 6.023 × 10²³
= 25.71 × 10²³ molecules
Thus, we can say that 25.71 × 10²³ molecules are there in 4.27 moles of tungsten (VI) oxide, [tex]WO_3[/tex].
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Ammonia burns in the presence of a copper catalyst to form nitrogen gas. 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g) ΔΗ = -1267 kJ What is the enthalpy change to burn 38.4 g of ammonia?
Answer:
-713 kJ
Explanation:
Step 1: Write the balaned thermochemical equation
4 NH₃(g) + 3 O₂(g) → 2 N₂(g) + 6 H₂O(g) ΔΗ = -1267 kJ
Step 2: Calculate the moles corresponding to 38.4 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
38.4 g × 1 mol/17.03 g = 2.25 mol
Step 3: Calculate the enthalpy change to burn 2.25 mol of ammonia
According to the thermochemical equation, 1267 kJ are released per 4 moles of ammonia that react.
2.25 mol × (-1267 kJ/4 mol) = -713 kJ
What three parts of your eye work together to create a clear image?
Answer:
cornea,Jens and pupil
tma Po yan
Which statements explain the relationship between photosynthesis and cellular respiration? Select two options.
The glucose that plants use for energy is made by animals in cellular respiration.
Glucose is a reactant in both photosynthesis and cellular respiration
The oxygen released by photosynthesis is breathed in by animals to break down glucose.
Carbon dioxide is a product of both photosynthesis and cellular respiration
The carbon dioxide released by animals is used to build glucose in photosynthesis.
Answer:
the 2nd and 5th
Explanation:
they are both correct
Answer:
b and d | Glucose is a reactant in both photosynthesis and cellular respiration. | Carbon dioxide is a product of both photosynthesis and cellular respiration.
Explanation:
hope this helps.
A. Direction: Identify the word or phrase being described in the sentence. Write your
answers in your notebook.
1. It is an electronic measuring instrument that combines several
measurement functions in one unit.
2. In diodes, what do the silver stripe represents?
3. This is an Electronic/Electrical component that stores energy in
the form of Electric Charge.
4. This allows you to change the function between volts, ohms, and
amps, and to change the scale of the meter.
5. In testing capacitor, if the multimeter shows very low resistance,
it means that the capacitor is .
6. These are components used to resist the flow of electric current.
7. It is a system used to determine the value of a resistor without
using a multimeter.
8. What defective capacitor that shows very low Resistance?
9. A type of transformer that is used to increase the output voltage.
10. A type of transformer that is used to decrease the output voltage.
Answer:
1. Multimeter
2. Cathode
3. Capacitor
4. Selector switch
5. Short or Shorted
6. Resistors
7. Resistor color coding
8. Open Capacitor
9. Step-up transformer
10. Step-down transformer
Explanation:
The above-described elements are electronic components. Resistors for instance are designed to resist the flow of electric current. They are also standardized such that a deviation from the set resistance level will indicate a problem. The capacitor is another electrical component that stores energy as an electrical charge. Knowledge of these electrical components and the ways they are tested will make a person proficient in electrical electronics.
