Answer:
B
disappears
Explanation:
Bbbbbbbbbb
What two layers of the earth are made of rock
Answer: There are two types of crust; oceanic and continental. Oceanic crust is denser and thinner and mainly composed of basalt.
Explanation:
The crust This is the outside layer of the earth and is made of solid rock, mostly basalt and granite. Oceanic crust is denser and thinner and mainly composed of basalt.
Answer:
The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere .
Explanation:
help me pleaseeeeee
Answer:
Arthropod (3)
Annelids (2)
Cnidarians (1)
Echinoderms (4)
Explanations:
I hope all this helps if u don't understand it let me know.
What is the empirical formula for a compound that is comprised of 54.0% sodium, 8.50% boron, and 37.5% oxygen by mass?
A) Na2B2O3.
B) Na3BO3.
C) Na3B2O2.
D) Na4BO4.
Answer:
B) Na3BO3.
Explanation:
Hello!
In this case, since percent compositions are used to identify the empirical formula of an unknown compound, we can assume we have 54.0 g of sodium, 8.50 g of boron and 37.5 g of oxygen, and we compute the moles of each one:
[tex]n_{Na}=54.0g*\frac{1mol}{23g} =2.35mol\\\\n_B=8.50g*\frac{1mol}{11g}=0.773mol\\\\n_O=37.5g*\frac{1mol}{16g}=2.34mol[/tex]
Now, we divide by the moles of boron as those are the fewest:
[tex]Na:\frac{2.35}{0.773}=3\\\\B:\frac{0.773}{0.773}=1\\\\O=\frac{2.34}{0.773}=3[/tex]
Thus, the empirical formula is B) Na3BO3.
Best regards!
i need the answer for this
Answer:
need points
Explanation:
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).
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.
Andesitic rock is an igneous rock with a composition in between that of basaltic and granitic igneous rock.
true or false
Answer:
Explanation:
intristing
What is the difference between a purine and a pyrimidine?
Answer: Adenine and guanine are the two purines and cytosine, thymine and uracil are the three pyrimidines. The main difference between purines and pyrimidines is that purines contain a sixmembered nitrogencontaining ring fused to an imidazole ring whereas pyrimidines contain only a sixmembered nitrogencontaining ring. They both are types or categories of nitrogen containing bases present in nuclei acids of DNA and RNA.
Purines are 2 Ring or Carbon Ring, Nitrogen containing bases. That consist of these 2 rings next placed next to each other. These examples include - Adenine and Guanine.
Pyrimidines are 1 or single Ring Nitrogen containing structures. There are 3 nitrogenous bases that are categorized as pyrimidines. Cytosine, Thymine, and Uracil.
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.
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.
HELPPPPPPPPP 35 POINTSSSSSS!!!!!FILL IN THE BLANKS with either "reduce" or "oxidize"
Magnesium is able to ——copper, and copper is able to —— magnesium.
Zinc is able to—— magnesium, and magnesium is able to—— zinc.
Copper is able to—— zinc, and zinc is able to—— copper.
Look at my screenshot:
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.
who want to play among us
Answer:
Meh i want to play
UwU
:)
Answer: yeah sure lad
Explanation:
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
Most of the elements in the periodic table can be described as:
A. metalloids
B. halogens
c. non-metals
D. metals
The answer would be metals :)
Which is the order of these solutions from strong acid to strong base?
Solutions:
household ammonia
battery acid
baking soda
stomach acid
antacid
A-stomach acid household ammonia battery acid antacid baking soda
B-battery acid stomach acid antacid baking soda household ammonia
C-battery acid stomach acid baking soda antacid household ammonia
D-stomach acid battery acid antacid baking soda household ammonia
Answer:
First is battery acid with a pH of 1, second is stomach acid with a pH of 1.5-3.5 (depends), third is antacid with a pH of 7, fourth is baking soda with a pH of 9, and finally, fifth is household ammonia with a pH of 11.
Here is a picture of the pH levels to better help you understand.
Answer:
b
Explanation:
When is my dad going to get the milk?
Answer:
joe.......
Explanation:
mama......
Which molecule/molecular compound is joined by a single covalent bond? O2 or N2 or Br2 or CO2?
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:
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:
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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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
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
Adaleigh is learning about renewable and non-renewable resources in her science class. She decides to take
a nature walk and makes notes of all the renewable resources that she sees. Which of the following is an
observation that Adaleigh could have made on her walk?
A. The seeds on the ground are going to grow into new trees.
B. The tallest trees had the most seeds around their bases.
C. When trees decay, they could eventually turn into coal.
D. Pine trees are older than oak trees.
Answer:
A. The seeds on the ground are going to grow into new trees.
Explanation:
Trees are renewable resources.
FeO+ PdF2 ---> FeF2+PdO balance please worth 50 points
Answer: FeO
Explanation:
Answer:
This is not worth 50 points liar
Explanation:
why are there different types of matter.
Answer:
solid ; liquid and gas........
100
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!
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
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)
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.
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