Explanation:
You should read the most important questions properly and you should look your syllabus of test.
You should read old questions of test
that were already asked.
Hydrogen and Oxygen combine to form water. In this chemical reaction, who represents the reactions(s)
A. water
B. oxygen and water
C.hydrogen and water
D. hydrogen and oxygen
What term is used to define when a substance reacts quickly with oxygen to produce light and heat?
A. rusting
B. sublimation
C. precipitation
D. burning
Answer:
I think it's a
Explanation:
not sure hssjkskaakakskksskksqoqkakskzksjsj
Answer: The answer is, D) Burning.
Explanation: Some moderator removed my last answer because someone reported it.
The sun is located at 1 astronomical unit from Earth. How far is the next closest star to Earth?
A. It is about twice as far from earth as the sun.
B. It is about 100 times as far from earth as the sun.
C. It is about the same distance from Earth as the
sun.
D. It is many thousands of times as far from the Earth as the sun.
answer:
d
Explanation:
sun 109 million miles
2 star trillion of miles
Which two groups of the periodic table do not contain any non-metal?
The 17th and 18th i think.. If by non-metal you mean no metal I think Its the 17th and 18th
hope this could help a bit.
Please help ASAP I’ll mark you as brainlister
Answer:
2
Explanation:
The balanced chemical equation for this reaction is:
2Na + K2S → 2K + Na2S
Meaning the coefficient for potassium (K) is 2.
Answer:
2 / 1 => 2 / 1
Which branch of chemistry would study how pollution effects marine life?
biochemistry
physical chemistry
materials chemistry
environmental chemistry
Answer: (D) environmental chemistry
Explanation:
The environmental chemistry is branch of chemistry would study how pollution effects marine life. option D is correct.
What is environmental chemistry?
Environmental chemistry is the study of the biochemical and chemical processes that occur in natural places like in forest, water bodies in air in soil and related to animals too.
Environmental chemistry is wide range of studies than air, water, soil, and chemicals. This also gives the brief account about the marine life with studying the life cycle of marine animals and plants too.
Therefore, environmental chemistry is branch of chemistry would study how pollution effects marine life. option D is correct.
Learn more about environmental chemistry, here:
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What is the energy change per gram of ice when an iceberg composed of pure water, cp = 2.06 J/(g·K), is heated from 25°C to 15°C?
A. 21 J
B. 0.21 J
C. 210 J
D. It is impossible to calculate without knowing the mass of the iceberg
Answer:
A. 21 J
Explanation:
Your temperature change is 10 degrees Celsius, or 10 Kelvin, it makes no difference either way.
Cp = 2.06 J/g•K
Multiply by the temperature change to just get J/g
2.06 J/g•K • 10 K = 20.6 J/g ≈ 21 J/g
21 J is the energy change per gram of ice when an iceberg composed of pure water, cp = 2.06 J/(g·K) which is heated from 25°C to 15°C. So, the correct option is A.
What is Heat?Heat is defined as the energy that is transferred from one body to another as a result of a difference in temperature, when two bodies at different temperatures are brought together, the energy transferred is that of the hotter body which flows towards the colder body.
In this case, according to the equation for the calculation of the heat during a heating process
[tex]Q= mC (T_f- T_i)[/tex]
It is possible to calculate mass per gram of ice by dividing both sides by removing m from the equation, we plug in the given specific heat and final and initial temperatures to get:
[tex]Q= 2.06 \frac{J}{g degree C} [-15 Degree C- (-25 Degree C][/tex]
[tex]Q= 20.6\frac{J}{g}[/tex] which is equals to 21° C
21 J is the energy change per gram of ice when an iceberg composed of pure water, cp = 2.06 J/(g·K) which is heated from 25°C to 15°C.
Therefore, the correct option is A.
Learn more about Heat, here:
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If Hydrochloric Acid and Calcium Carbonate were combined would the reaction that occurs be endothermic or exothermic? Why?
Answer:
endothermic
Explanation:
more energy is being released and heat is being required to do the process.
7
Why might living in a high-pollution area have a negative effect on a person's
thyroid?
I
2N2 + 502 --> 2N205
Based on the above reaction, if 7 moles of Ny react completely, how many moles of Oz must also react?
ASAP LOOK AT PICTURE
Answer:
wait are you talking about the bottom question??
All changes in phase (solid-liquid-gas) are
Answer:
States of matter
Explanation:
Three states of matter
Covert 50oC to k
(I’ll mark you as brainlister)
Answer:
323 K
Explanation:
To convert Celcius to kelvin first you need to remember this equation:
C + 273 = K (K = kelvin and C = celsius)
Next, you substitute with what you have given:
50 + 273 = K
Solve the equation by adding 50 and 273
k = 323
A student placed a solid in a liquid, which produced the results shown in the following diagram.
solid: 20°C
OOO
gas bubbles
liquid: 20°C
1
2
Which of the following MOST likely took place?
A. a chemical reaction
chemical
o
O B. a phase change
C. a nuclear reaction
D. a destruction of mass
The most likely to take place when a solid is placed in a liquid at room temperature ( i.e. 20°C ) is ; ( A ) A chemical reaction
Although your question lacks the required diagram a general answer is provided within the scope of your question
When a solid at 20°C is placed inside a liquid also at 20°C in the laboratory the emergence of gas bubbles shows that there has been a chemical change between the solid and liquid reactant ( i.e. a chemical reaction has taken place ).
Hence we can conclude that what is most likely to have taken place in this situation is a Chemical reaction.
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PLEASE HELP "Which of the following substances would have the lower concentration of hydrogen ions ?"
Please help I want the answer
A) Since both are carbons with the only difference in the number of neutrons,
They are called Isotopes
B) Carbon - 12 has 6 protons and 6 neutrons, while Carbon-13 has 6 protons and 7 neutrons,
Therefore Carbon-12 and Carbon-13 have the same number of protons
C) Carbon - 12 has 6 protons and 6 neutrons, while Carbon-13 has 6 protons and 7 neutrons,
Therefore Carbon-12 and Carbon-13 has different numbers of neutrons
D) Sorry i don't know any uses of Carbon-12 and Carbon-13, you might have to research to get it.
E or F) Sodium 23 has 12 neutrons and 11 electrons, because its mass number 23, atomic number is 11 and since protons and electrons count is same, the number of neutrons = mass number - atomic number = 23 - 11 = 12 neutrons
Happy to help :)
If you need any more help, feel free to ask
After a skydiver deploys
his parachute, his rate of
speed decreases.
Answer:
As a skydiver falls, he accelerates downwards, gaining speed with each second. The increase in speed is accompanied by an increase in air resistance (as observed in the animation below). This force of air resistance counters the force of gravity. As the skydiver falls faster and faster, the amount of air resistance increases more and more until it approaches the magnitude of the force of gravity. Once the force of air resistance is as large as the force of gravity, a balance of forces is attained and the skydiver no longer accelerates. The skydiver is said to have reached a terminal velocity.
6.
Why are estuaries home to diverse marine life not found elsewhere?
is hrimming with
Answer:
Estuaries are bodies of water where rivers meet the sea or a large lake. Rivers spread out and slow when they meet the sea, creating unique conditions that are not found elsewhere. They provide homes for diverse wildlife, including popular fish species.
If peanut butter wasn't called peanut butter.. what would it be called?
Answer:
I have no idea
Explanation:
Calculate the pH of the solutions with the following [OH-].
what is the mass of [tex]Fe^{2+}[/tex] in 5 tablets of iron if the number of moles of [tex]Fe^{2+}[/tex] is 4.2225 x [tex]10^{-4}[/tex] mol.
[ Ar = Fe, 56 ]
Answer:
Approximately [tex]0.11823\; \rm g[/tex] in total for the five tablets.
(Approximately [tex]2.3646 \times 10^{-2}\; \rm g[/tex] per tablet.)
Explanation:
The relative atomic mass of an element is the ratio between:
the mass of one atom of this element, and the mass of one-twelfth of a carbon-[tex]12[/tex] atom.The definition of moles ensures that the relative atomic mass of an element is approximately numerically equal to the mass (measured in grams) of one mole of the atoms of this element.
The question states that the relative atomic mass [tex]A_{\rm r}[/tex] of iron is [tex]56[/tex]. In other words, the mass of one mole of iron [tex]\rm Fe[/tex] atoms would be approximately [tex]56\; \rm g[/tex].
The question is asking for the mass of some amount of [tex]\rm Fe^{2+}[/tex] ions. Each [tex]\rm Fe^{2+}\![/tex] ion contains two fewer electrons than a neutral [tex]\rm Fe[/tex] atom. Hence, [tex]4.2225 \times 10^{4}\; \rm mol[/tex] of [tex]\rm Fe^{2+} \![/tex] ions might be lighter than the same number of [tex]\rm Fe \![/tex] atoms by a very small extent: The mass of one mole of electrons is approximately [tex]5 \times 10^{-4}\; \rm g[/tex], much smaller than the mass of the same number of [tex]\!\rm Fe[/tex] atoms (approximately [tex]56\; \rm g[/tex].)
Estimate the mass of these [tex]4.2225 \times 10^{4}\; \rm mol[/tex] of [tex]\rm Fe^{2+}[/tex] ions using the mass of the same number of [tex]\rm Fe[/tex] atoms:
[tex]\begin{aligned}&m({\rm Fe^{2+}}) \\ &\approx m({\rm Fe}) \\ &\approx 4.2225 \times 10^{-4}\; \rm mol \\ &\quad\quad \times 56\; \rm g \cdot mol^{-1} \\ &\approx 2.3646 \times 10^{-2}\; \rm g \end{aligned}[/tex].
Five of these tablets would contain approximately [tex]5 \times 2.3646 \times 10^{-2}\; \rm g \approx 0.11823\; \rm g[/tex] of [tex]\rm Fe^{2+}[/tex] ions.
As Which is a case of drug abuse?
A.
taking an analgesic whenever you have a headache, no matter how mild
B.
taking double the dosage, by accident, of a medicine that your doctor has prescribed
C.
taking a tranquilizer every night when the label warns not to take it on consecutive nightspirin is a widely used drug. What kind of medicine is it?
HELPP asap I’ll mark you as brainlister!!!!!!
Elizabeth collects different types of rocks whenever she goes on vacation. She has rocks that contain shiny crystals, grainy rocks, and rocks that are smooth. These rocks are formed? by different processes. Which of the following is NOT a process by which rocks are formed?
A. freezing of sediments.
B. compaction of sediments.
C. heat and pressure within the Earth
D. cooling of magma at Earth's surface
Answer:
It should be A. I've never heard of freezing of sediments
A beaker contains a sample of water with a mass of 325 grams. The water in the beaker
is boiled and weighed again after it cools. The new mass of the water is 305 grams. In
this example of the conservation of matter in physical changes,
A. the mass is less after it cools because water has less mass as a gas.
B. the mass of the water was 305 grams and the mass of the water vapor was 20 grams.
C. the process of boiling destroyed 20 grams of the water and left 305 grams of water.
D. the heat energy created by boiling water makes up the rest of the mass.
Answer: a
Explanation:
Bc I just did it and yeah
help me i mark brain thing
Answer:
Becuase they can go through mountains and hills, they curve of of those.
What color is an orange?
Answer:
orange
Explanation:
What is the mass in grams of 4.8 moles of Calcium Hydroxide?
Answer:
355.2 grams
Explanation:
m = M×n= (40 + 2(16+1))×4.8= 355.2 (g)
The nucleus of an atom is ______ charged
Answer:
The nucleus of an atom is positively charged.
Explanation:
The nucleus of an atom is positively charged because :
The nucleus is a small dense region at the center of the atom. It consists of a positive protons and neutral neutrons. so, It has an overall positive charged.
Explain why a climax community is not always a forest.
Given 2Na + Cl2=2NaCl, what is the excess reactant? What is the limiting reactant?
Answer: The limiting reactant is Na
Explanation: