Answer:Since dinosaurs are thought to be over 65 million years old, the news is stunning - and more than some could tolerate. After the AOGS-AGU conference in Singapore, the abstract was removed from the conference website by two chairmen because they could not accept the findings. Unwilling to challenge the data openly, they erased the report from public view without a word to the authors. When the authors inquired, they received this letter:
Explanation:
i do not own my copyrights
what is an atomic element of carbon
Answer: do u mean atomic number? The atomic number for carbon is 6
Explanation:
Answer:
Chemical element
Explanation:
Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up only about 0.025 percent of Earth's crust.
is pure water a solution
Answer: No because a solution is a homogeneous MIXTURE of two or more substances. Water is a pure substance. It is made of hydrogen and oxygen, but shares none of their properties. So it’s pure.
Explanation:
Which equation best represents the balanced net ionic equation for the reaction that occurs when aqueous solutions of lithium phosphate and magnesium nitrate are mixed?
Answer:
2 PO₄³⁻(aq) + 3 Mg²⁺(aq) ⇒ Mg₃(PO₄)₂(s)
Explanation:
Let's consider the molecular equation that occurs when aqueous solutions of lithium phosphate and magnesium nitrate are mixed.
2 Li₃PO₄(aq) + 3 Mg(NO₃)₂(aq) ⇒ 6 LiNO₃(aq) + Mg₃(PO₄)₂(s)
The complete ionic equation includes all the ions and insoluble species.
6 Li⁺(aq) + 2 PO₄³⁻(aq) + 3 Mg²⁺(aq) + 6 NO₃⁻(aq) ⇒ 6 Li⁺(aq) + 6 NO₃⁻(aq) + Mg₃(PO₄)₂(s)
The net ionic equation includes only the ions that participate in the reaction and insoluble species.
2 PO₄³⁻(aq) + 3 Mg²⁺(aq) ⇒ Mg₃(PO₄)₂(s)
When [H+] = 4.0 × 10–9 M in water at 25°C, then
Kw =1.0×10–14.
b. pOH = 7.
c. [H3O+] = [OH–].
d. pH= 7
e. A-D are all correct
Answer:
a. Kw = 1.0 × 10⁻¹⁴
Explanation:
a. Let's consider the self-ionization of water.
2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻
The ion-product of water (Kw) at 25 °C is:
Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴
c. Considering [H⁺] = [H₃O⁺] = 4.0 × 10⁻⁹ M, the concentration of OH⁻ is:
[OH⁻] = 1.0 × 10⁻¹⁴/[H₃O⁺] = 2.5 × 10⁻⁶ M
b. We can calculate the pOH using the following expression.
pOH = -log [OH⁻] = -log 2.5 × 10⁻⁶ = 5.6
d. We can calculate the pH using the following expression.
pH = -log [H⁺] = -log 4.0 × 10⁻⁹ = 8.4
When [H+] = 4.0 × 10–9 M in water at 25°C, then the [tex]Kw =1.0\times 10^-^1^4.[/tex]
What is dissociation constant?
Kw is the dissociation constant or ionization constant of water.
The self-ionization of water will be
[tex]\rm 2 H_2O(l) = H_3O^+(aq) + OH^-[/tex]
The dissociation constant of the water at 25°C will be
[tex]\rm Kw = [H_3O^+][OH^-] = 1.0 \times 10^-^1^4[/tex]
Thus, the correct option is a. [tex]Kw =1.0\times 10^-^1^4.[/tex]
Learn more about dissociation constant
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The heat of vaporization of diethyl ether is . Calculate the change in entropy when of diethyl ether boils at . Be sure your answer contains a unit symbol. Round your answer to significant digits.
Answer:
[tex]\Delta S=900\frac{J}{K}[/tex]
Explanation:
Hello!
In this case, since the information is not missing, the following one will be used as it is found on similar problems:
[tex]\Delta h=26.7kJ/mol\\T_b=34.6\°C\\m=769.0g[/tex]
In such a way, we use the following equation to compute the entropy:
[tex]\Delta S=\frac{n\Delta h}{T_b}[/tex]
Whereas n (moles) are computed by using its molar mass (74.14 g/mol) as follows:
[tex]n=769.0g*\frac{1mol}{74.14g}=10.4mol[/tex]
[tex]\Delta S=\frac{10.4mol*26.7\frac{kJ}{ml} }{(34.6+273.15)K}\\\\\Delta S=0.900 \frac{kJ}{K} \\\\\Delta S=900\frac{J}{K}[/tex]
Best regards!
Mg + P4 → Mg3P2
Assuming an unlimited amount of phosphorous (P4), how many grams of Mg are needed in order to
produce 1200.00 grams of Mg3P2?
Answer:
648.7g of Mg must be added
Explanation:
Based on the reaction:
3Mg + 1/2P4 → Mg3P2
3 moles of Mg produce 1 mole of Mg3P2
To solve this problem we neeed to find the moles of Mg3P2 in 1200g. With these moles and the chemical reaction we can finf moles of Mg and its mass:
Moles Mg3P2 -Molar mass: 134.88g/mol-:
1200.0g Mg3P2 * (1mol / 134.88g) = 8.897 moles of Mg3P2
Moles Mg:
8.897 moles of Mg3P2 * (3mol Mg / 1mol Mg3P2) = 26.69 moles of Mg
Mass Mg -Molar mass: 24.305g/mol-:
26.69 moles of Mg * (24.305g / 1mol) =
648.7g of Mg must be added100
80
100 mL
water vapor
Which statement describes what will happen if a student pushes the plunger
to compress the water vapor?
A. The total number of water particles will increase.
B. The amount of energy in the water particles will decrease.
C. The amount of empty space between the water particles will
decrease
D. The total volume of the water particles will increase
I will mark brainliest
Answer:
Explanation:it is c
Answer:
C The amount of empty space between the water particles will decrease
Explanation:
I just took the quiz, have a nice day!
why are there different types of matter.
Answer:
solid ; liquid and gas........
Please help me ASAP
Why is it possible for an active metal like aluminum to be useful as a structural metal?
Answer:
Aluminum even after being an active metal is used as a structural metal due to its toughness, high strength, lightweight, and resistance to the process of corrosion. It is resistant to corrosion as its reactivity gets suppressed due to the formation of an aluminum oxide film which is protective in nature, on its surface. Passivation is the term for the formation of the protective coating.
If a person tells you she is 6 feet tall, is she basing that measurement on customary units or metric units?
customary
metric
Answer:
Customary
Explanation:
Answer:
Customary
Explanation:
FeO+ PdF2 ---> FeF2+PdO balance please worth 50 points
Answer: FeO
Explanation:
Answer:
This is not worth 50 points liar
Explanation:
Which molecule/molecular compound is joined by a single covalent bond? O2 or N2 or Br2 or CO2?
What do you think is the common link between each of the phenomena shown?
Answer:
sounds wave
Explanation:
From alarm, microwave, laser, TV, water waves and a musical instrument, everything release sounds.
(Not the same)
If it convinced you please add this in the brainlist
17 Which changes decrease the rate of reaction between magnesium and air?
1.heating the magnesium to a higher temperature
2.using a higher proportion of oxygen in the air
3.using magnesium ribbon instead of powdered magnesium
A 1, 2 and 3
B 1 only
C 2 only
D 3 only
Using magnesium ribbon instead of powdered magnesium decrease the rate of reaction between magnesium and air.
What is rate of reaction?Rate of reaction tells about the duration of the completion of the reaction.
Rate of any reaction is directly proportional to the concentration and surface area of the reactant, temperature, catalyst, no. of collision, activation energy, etc.
So, if we magnesium in the ribbon instead of powdered magnesium the surface area of the reactant side decreases which results in the decrease of the rate of reaction.
Hence, option (D) is correct i.e. rate of reaction decreases on using magnesium ribbon instead of powdered magnesium.
To know more about rate of reaction, visit the below link:
https://brainly.com/question/1898560
7. Which of the following pairs of elements is most likely to form an ionic
compound?
b. potassium and neon
c. barium and aluminum
a. oxygen and fluorine
d. lithium and bromine
Answer:
not sure if this us right but oxygen and fluorine? I learned chem but I forgot about it kinda sorry
who want to play among us
Answer:
Meh i want to play
UwU
:)
Answer: yeah sure lad
Explanation:
How many molecules of carbon tetrachloride are equal to 0.25moles
A 2.52 L container of oxygen gas at 28.6 °C is heated to 45.9 °C. Assuming that the volume of the container can vary, what is the new volume of the gas?
Answer:
4.04433566 L (433566 repeating)
Explanation:
2.52 is divided by 28.6 is 0.0881118 (881118 repeating). multiply 0.0881118 (881118 repeating) by 45.9 to get 4.04433566 L (433566 repeating).
The free flow of electrons is responsible for
Answer:
An electrical phenomenon is caused by flow of free electrons from one atom to another. The characteristics of current electricity are opposite to those of static electricity. Wires are made up of conductors such as copper or aluminum.
Explanation:
from google
In what way is cellular respiration like breathing?
Answer:Cellular respiration is not the same as breathing, but they are closely related
Explanation: When you breathe in, you take in the oxygen your cells need for cellular respiration. When you breathe out, you get rid of carbon dioxide that your cells produce during cellular respiration.
How many grams of F2 are in 3.45 x 1022 molecules of F2?
Answer:
Mass = 2.16 g
Explanation:
Given data:
Number of molecules of F₂ = 3.45 × 10²²
Mass in gram = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
3.45 × 10²² molecules ×1 mol / 6.022 × 10²³ molecules
0.57× 10⁻¹ mol
0.057 mol
Mass in gram :
Mass = number of moles × molar mass
Mass = 0.057 mol × 37.9 g/mol
Mass = 2.16 g
How are ionic compounds named?
Answer:
Ionic compounds are neutral compounds made up of positively charged ions called cations and negatively charged ions called anions. For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion.
Explanation:
Hope this helps.
500 grams of an unknown substance gains 23000 J of heat as it is heated from a temperature of 250C to 1250C. Using mathematical computation and the chart below, determine the identity of the unknown substance.
Answer:
The given substance is cast iron.
Explanation:
Given data:
Mass of substance = 50 g
Heat absorbed = 23000 J
Initial temperature = 250°C
Final temperature = 1250°C
Which metal is this = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 1250°C - 250°C
ΔT = 1000°C
23000 j = 50 g ×c ×1000 °C
23000 J = 50,000 g. °C×c
c = 23000 J /50,000 g. °C
c = 0.46 J/g.°C
The given substance is cast iron.
21.4 L of gas at 42.3 °C and 681 mm Hg are heated to 221 °C, and the pressure is changed to 248 mm Hg. What is the new volume?
Answer:
V₂ = 90.42 L
Explanation:
Given data:
Initial volume = 21.4 L
Initial pressure = 681 mmHg (681/760=0.89 atm)
Initial temperature = 42.3 °C (42.3 +273 = 315.3 K)
Final temperature = 221°C (221+273 = 494 K)
Final volume = ?
Final pressure = 248 mmHg(248/760 =0.33 atm)
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
P₁V₁/T₁ = P₂V₂/T₂
V₂ = P₁V₁T₂/T₁P₂
V₂ = 0.89 atm × 21.4 L × 494 K / 315.3 K × 0.33 atm
V₂ = 9408.72 L /104.05
V₂ = 90.42 L
All of these affect weather except!
A. Air pressure
B. Humidity
C. Barometer
D. Wind speed
Answer:
C.Barometer
Explanation:
is chromate polar or nonpolar?
Answer:
i THINK so
Explanation:
im not sure tho sorry if wrong
Andesitic rock is an igneous rock with a composition in between that of basaltic and granitic igneous rock.
true or false
Answer:
Explanation:
intristing
List three things, other than the name, symbol, atomic number, and average atomic mass, you can discover about an element using the periodic table in Figure 6.9.
Answer: State of matter, Subcategory in the metal-metalloid-nonmetal trend, and electrons per shell.
Explanation:
d Which properties of plastics cause a problem when the container is empty?
Answer: Both of these are of great concern to human health. BPA is used in many things including plastic bottles and food packaging materials. Over time the polymer chains of BPA break down, and can enter the human body in many ways from drinking contaminated water to eating a fish that is exposed to the broken down toxins.
Explanation:
I think you will get it