Answer:
hello hope this helps :)
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
One of the waste byproducts of a nuclear reactor using uranium-235 is strontium-90 with half-life of about 28 years. If we have 100 pounds of this radioactive waste:
Answer:
(a) 140 years
(b) 3.125 pounds
Explanation:
QuestIons
(a) How long is five half-life
(b) How much radioactive strontium is left after five half-life
Given that:
Half-life is about 28 years; &
There are 100 pounds of this radioactive waste
Five half-life will be;
= 28 × 5
= 140 years
The amount of radioactive remaining after five half-life is:
[tex]= 100 \times( \dfrac{1}{2}) ^5[/tex]
= 100 × 0.03125
= 3.125 pounds
What is nuclear fusion what role does it play in the sun
Answer:
Nuclear fusion is when two atomic nuclei combine and form one nucleus. Nuclear fusion generates all of the Sun's energy. Inward pulling by the Sun's gravity is counteracted by outward pushing by the Sun's nuclear fusion; this balance keeps the sun from collapsing or exploding.
Explanation:
Answer:
it converts mass into energy and hydrogen into helium.
Explanation:
Nuclear fusion, the source of all the energy so generously radiated by the Sun
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:
What is a net ionic equation?
A. An equation that shows all substances as compounds
B. An equation that shows all dissolved compounds as ions
C. An equation showing only what is involved in the reaction
D. An equation that is balanced on both sides
Answer:
the answer is C
Explanation:
i took a test and it said c was the answer
The correct option is C.
In the complete equation of a chemical reaction, the complete symbols of reactants and products are written along with states of matter under conditions at which the reaction is taking place.
In the net ionic equation of a chemical reaction, only those chemical species are written which directly participate in the chemical reaction. The mass and charge in the net ion equation must be balanced.So, the correct option is c.
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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.
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Can anyone solve the little chart at the bottom?
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:
Jada Peterson
Wanda often looks through her telescope at the details of different bodies in our solar system. What skill is Wanda using?
A:observing
O concluding
O experimenting
hypothesizing
Save and exit
1
Answer: A
Explanation:
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.
4. How many moles of water are produced when 3.25 moles of CO2 are formed?
Answer:
6.50 mol
Explanation:
The question is incomplete but I looked it up on the web.
How many moles of water are produced when 3.25 moles of CO₂ are formed during the combustion of methyl alcohol (CH₃OH)?
Step 1: Write the balanced equation
2 CH₃OH + 3 O₂ → 2 CO₂ + 4 H₂O
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of CO₂ to H₂O is 2:4.
Step 3: Calculate the moles of water formed with 3.25 moles of carbon dioxide
We will use the established molar ratio.
3.25 mol CO₂ × (4 mol H₂O/ 2 mol CO₂) = 6.50 mol H₂O
7. A. How many moles of Calcium hydroxide (CaOH2) are needed to completely react with 14.5 mol of Phosphoric acid (H3PO4)?
2 H3PO4 + 3 Ca(OH)2 → 6 H(OH) + Ca3(PO4)2
a. How many moles of water (HOH) will be produced?
b. How many moles of Calcium Phosphate (CaOH2) will be produced?
Answer:
moles of calcium hydroxide= 21.75 mol
a) 43.5 mol
b) 7.25 mol
Explanation:
Please see the attached picture for the full solution.
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 :)
Examples of nuclear fusion and fission.
Answer: For example, uranium can fission to yield strontium and krypton. Fusion joins atomic nuclei together. The element formed has more neutrons or more protons than that of the starting material. For example, hydrogen and hydrogen can fuse to form helium.
Explanation:
Hope this helped!
Answer:
Explanation:For example, uranium can fission to yield strontium and krypton. Fusion joins atomic nuclei together. The element formed has more neutrons or more protons than that of the starting material. For example, hydrogen and hydrogen can fuse to form helium.
if you have 4 moles of n2 and 6 moles of h2, how much would be produced?
Answer:
8 i think
Explanation:
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.
What is the molar mass of h2
Answer:
The answer is one
Explanation:
I will just type any rubbish here bcuz my answer should be more than 20 words..... Just know the answer is 1
The phase change between white tin and gray tin is difficult to observe directly. Both substances can be burned, however. From these equations, calculate AHⓇ for the conversion of gray tin into white tin:
Sn(s, white) + O2(g) + SnO2(g) AH = -580.69 kJ
Sn(s, gray) + O2(g) + SnO2(g) AH° = -582.78 kJ
AH = _________ kJ
Answer: Thus [tex]\Delta H[/tex] for the conversion of gray tin to white tin is -20.9 kJ
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The final reaction is
[tex]Sn(s, gray)\rightarrow Sn(s, white)[/tex] [tex]\Delta H=?[/tex]
The intermediate balanced chemical reaction will be,
[tex]Sn(s, gray)+O_2(g)\rightarrow SnO_2(g)[/tex] [tex]\Delta H^0=-582.78kJ[/tex] (1)
[tex]Sn(s, white)+O_2(g)\rightarrow SnO_2(g)[/tex] [tex]\Delta H^0=-580.69kJ[/tex] (2)
substarcting (2) form (1) we get
[tex]\Delta H=\Delta H_1-\Delta H_2[/tex]
[tex]\Delta H=-582.78-(-580.69kJ)[/tex]
[tex]\Delta H=-20.9kJ[/tex]
what is meant by the term quantitative?
A) number measurement
B) words & explanation
Answer:
a) number measurement
Explanation:
relating to, measuring, or measured by the quantity of something rather than its quality.
Answer:
number and measurement
Explanation:
Quantitative is an adjective that simply means something that can be measured. For example, we can count the number of sheep on a farm or measure the gallons of milk produced by a cow.
Why does oxygen have a smaller atom size than nitrogen?
Answer:
The eight protons in oxygen atom's nucleus will exert more force than nitrogen's seven electrons. Also, oxygen has same number of shells as nitrogen. Thus electrons in oxygen atom will be closer to nucleus than in the case of nitrogen. When electrons are closer it means atomic radius is smaller.
Hope this helps! :)
here's the answers.................
Can someone help with 1 2 3 please I give you brainlest
Answer:
1. Option C : oppositely charged
2. Option B : positively charged
3. Option D : negatively charged
The sun is the biggest source of visible_
energy caused by the movement of waves of
_____
Answer:
the sun is the biggest source of visible (solar?) energy caused by the movement of waves of (electromagnetic?)
Not confident sry :(
Explanation:
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.
When is my dad going to get the milk?
Answer:
joe.......
Explanation:
mama......
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.
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:
What else is produced when sodium carbonate decomposes?
Na2CO3 → Na2O + _________
Answer:
CO2
Explanation:
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:
Why is cellular respiration important?
A or B?
A. It changes energy in glucose into energy that can be used.
B. It changes radiant energy into chemical energy for all living things.
In the reaction __S+3O2→2SO3, what coefficient should be placed in front of the S to balance the reaction?
Question 1 options:
1
2
3
Answer:
2
Explanation:
because on the product side you have 2 sulfurs so you need 2 on the reactant side.
Answer the in under 30 minutes and I will give brainliest
After which event in Indonesia did one of the worst tsunamis form?
a hurricane
a volcanic eruption
a landslide
an earthquake
Answer: I believe the answer is an earthquake.
Explanation: Sorry If I am wrong!
Answer:
earthquake
Explanation:
I took the k12 test