Answer: opaque means not able to see through. An example is that a window is not opaque because you can see through it, but a rock is opaque.
Answer:
Opaque Definition below:
Explanation:
not able to be seen through; not transparent.
Hope it helps :)
please help mw with this
Answer:
I cannot see any picture
Explanation:
Please put a picture
Answer:
sure what's the question
Explanation:
1. Amy's science teacher shows her class a model of an atom. Why is a model useful for studying atoms?
A. All atoms exist in the gas phase, and atmospheric gases are invisible.
B. A model is helpful to observe the behavior of the parts of an atom.
C. The parts of an atom cannot be directly observed.
D. A model of an atom is the same for all atoms.
Answer:
The parts of an atom cannot be directly observed.
Explanation:
An atom is the smallest indivisible particle of a substance that can take part in a chemical reaction.
Atoms are not observed with naked eyes because they are found in the realm of very small particles. It is impossible to observe the parts of an atom directly.
As a result of this, models suffice in explaining the parts of an atom. Hence the answer.
7. What is the wavelength of a 4.34 x 10^15 /s wave?
Among electromagnetic waves, UV rays are most dangerous because exposure to these radiation cause serious problems in living organism. The wavelength of wave is 6.9x 10⁻⁸m.
What is electromagnetic wave?Electromagnetic wave is a wave which contain two component one is electric component and other is magnetic component. The electric and magnetic component are perpendicular to each other. There are so many wave that comes under electromagnetic wave like infrared wave , radio wave, light wave.
There is a relation between frequency of wave, and wavelength of wave
Mathematically,
ν=c÷λ
where,
ν=frequency of light=4.34 x 10¹⁵s⁻¹
c is speed of light that is 3×10⁸m/s
λ is the wavelength of light=?
Substituting all the values
4.34 x 10¹⁵=3×10⁸m/s÷λ
λ= 3×10⁸÷4.34 x 10¹⁵
λ=6.9x 10⁻⁸m
Therefore, the wavelength of wave is 6.9x 10⁻⁸m.
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As continents come together to form a supercontinent,
a. the ocean that jad separated them disappears
b. a giant ocean forms on the outside of the supercontinent
c. mountain ranges rise where continental plates converge
d. all of these
ASAP MULTIPLE CHOICE WILL MARK BRAINLIEST
A specific, electrically neutral atom of boron contains a total of 16 particles (protons, neutrons, and electrons).
What is the mass number of this atom of boron?
5
6
11
21
Answer:
11
Explanation:
which of the following is a compound?
how has thermal energy, heat, and temperature change?
thermal energy leads to an increase in the kinetic energy also increasing in temperature hope this helped!
Answer:
thermal energy leads to an increase in the kinetic energy also increasing in temperature This is known because temperature is in fact the measure of the average kinetic energy of the molecules.
Explanation:
hope this helps❤️
When a change of substance occurs, and when solutions are
made, the changes that take place are known as
changes.
Physical or chemical change
Answer:
They are known as physical changes
The correct name for Fe 2(SO 4) 3 is -
Answer:
Iron (III) sulfate
Explanation:
Which is the atomic number of an alkali metal?
10
11
12
13
Answer:
11 is the atomic number of alkali metal
Explanation:
The Group 1 elements are called the alkali metals. ... All the Group 1 elements are very reactive . They must be stored under oil to keep air and water away from them. Group 1 elements form alkaline solutions when they react with water, which is why they are called alkali metals.
what ions are present in solution sodium carbonate
The resulting solution is composed of separate sodium ions and carbonate ions surrounded by water molecules.
ASAP MULTIPLE CHOICE WILL MARK BRAINLIEST
An atom of gallium has 31 protons and a mass number of 70.
What is the atomic number for an atom of gallium?
31
35
39
70
Answer:
31
Explanation:
50:06
Elements are organized on the periodic table based on their properties. Which statement correctly predicts and explains the chemical reactivity of two different metals?
Barium (Ba) is less reactive than calcium (Ca) because the valence electrons in calcium atoms are farther from the nuclei and harder to remove.
Strontium (Sr) is more reactive than magnesium (Mg) because the valence electrons in strontium atoms are farther from the nuclei and harder to remove.
Rubidium (Rb) is more reactive than sodium (Na) because the valence electrons in sodium atoms are closer to the nuclei and easier to remove.
Lithium (Li) is less reactive than potassium (K) because the valence electrons in lithium atoms are closer to the nuclei and harder to remove.
Answer:
Rubidium belong to Alkaline group 1, and
Strontium belong to Alkaline group 2.
Explanation:
We know that elements are organized on the periodic table based on their properties. The statement correctly predicting and explaining the chemical reactivity of two metals is given below -Rubidium (Rb) is more reactive than strontium (Sr) because strontium atoms must lose more electrons.
1. What was the name of battle where the "shot heard around the world" happened?
What color of the spectrum contains the least amount of energy?
A. Red
B. Brown
C. Green
D. Violet
Answer:
red
Explanation:
Which of these is NOT a type of natural force? A) gravity B) friction C) throwing D) magnetism
Throwing isn't classified as a force so I'd say C but it is a force just not a type
Answer:
C- throwing
Explanation:
You physically have to throw it while the other forces act on their own.
How are protons, neutrons, and electrons different?
Answer:
Although similar in mass, protons are positively charged, while neutrons have no charge. Therefore, the number of neutrons in an atom contributes significantly to its mass, but not to its charge. Electrons are much smaller in mass than protons, weighing only 9.11 × 10-28 grams, or about 1/1800 of an atomic mass unit.Explanation:
Hope this helpsWhat do you call this process that happened in crayons and candles where it’s liquid phase turned into solid?
Answer:
Freezing/Solidification
Describe two ways to separate a mixture and when you would you use it
Answer:
Filtration separates solids of different sizes.
Evaporation removes a liquid from a solution to leave a solid material.
Explanation:
Have a nice day.
2NaOH+CO2----->Na2CO3+H2O
calculate the mass of sodium carbonate produced when 10.0 g of sodium hydroxide reacts with carbon dioxide.
Answer:
13.2 g Na2CO3
Explanation:
Convert 10.0 g NaOH to mol.
10.0 g x 1 mol/39.997 g = 0.250 mol
Use mol ration given by the equation: 2 mol NaOH to 1 mol Na2CO3
0.250 mol NaOH x 1 mol Na2CO3/2 mol NaOH = 0.125 mol Na2CO3
Finally, convert the moles of Na2CO3 to grams.
0.125 mol Na2CO3 x 105.99 g/1 mol = 13.2 g
According to stoichiometry,13.25 g of sodium carbonate is produced when 10 g of sodium hydroxide reacts with carbon dioxide.
What is stoichiometry?It is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.
For the given reaction according to stoichiometry 2 molecules of sodium hydroxide react to give 1 molecule of sodium carbonate.
That is 80 g sodium hydroxide gives 106 g sodium carbonate
∴10 g sodium hydroxide will produce 10×106/80=13.25 g of sodium carbonate.
Thus, 10 g sodium hydroxide produces 13.25 g of sodium carbonate.
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वार्षि
एउटा व्यक्तिले रु. 46875 को कर्जा लिएछ । यदि प्रतिवर्ष प्रति रुपैयाँ चक्रिय व्याजदर 4 पैसा भए कति वर्षमा रु. 5853 च.
25 ETSIT ? (A person took loan of Rs 46875. If the rate of compound interest is 4 paisa per rupee
year, in how many years will the compound interest be Rs 5853.) [2065 B, 067 D] Ans: 3
तार्षिक
पत्ता
Rs
200/-
Answer:
3 years
Explanation:
P= Rs 46875
R= 4 Pisa per rupee per year = 4% per annum
C. I = Rs 5853
t= time (the unknown)
Given;
Amount= P(1 + R/100)^t
Amount = (P + CI)
(46875 + 5853) = 46875 (1 + 4/100)^t
1.124864 = (1 + 4/100)^ t
1.124864 = (1.04)^t
t= 3 years
compare catalytic and thermal cracking
Answer:
Catalytic cracking is an important process in the oil industry where petroleum vapor passes through a low-density bed of catalyst, which causes the heavier fractions to 'crack' producing lighter more valuable products
Thermal cracking is an extraction process in which hydrocarbons such as crude oil are heated to a high temperature to break the molecular bonds. Thermal cracking is a refining process in which heat and pressure are used to break down, rearrange, or combine hydrocarbon molecules.
Explanation:
The theory of continental drift was widely unaccepted until scientists started using ________ the map the ocean floor.
A. Maps
B. SONAR (Sound Navigation Ranging)
C. Submarines
D. Volcanoes
plss helppp
Answer:
B Sonar
Explanation:
The theory of continental drift was widely unaccepted until scientists started using SONAR (Sound Navigation Ranging) the map the ocean floor. Therefore, option (B) is correct.
What is the SONAR?Sonar has full-form sound navigation and ranging which is a technique that uses sound propagation usually underwater to navigate, measure distances, and communicate with or detect objects.
Sonar can be used as a measurement of the echo characteristics of "targets" in the water. Sonar is used for robot navigation, while SODAR is used for atmospheric investigations.
The frequencies used in sonar systems vary from very low (infrasonic) frequency to extremely high frequency (ultrasonic). Ultrasonic waves are used in SONAR because they travel deep into the water without losing their power and their frequency ranges from 20Hz to 20,000Hz.
SONAR showed the mid of the Atlantic ridge is dividing plates such as the north Atlantic from the European plate which provides evidence of continental drift.
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The half-life of tritium (H-3) is 12.3 years. If 48.0mg of tritium is released from a nuclear power plant during the course of a mishap, what mass of the nuclide will remain after 49.2 years?
Answer:
The amount left after 49.2 years is 3mg.
Explanation:
Given data:
Half life of tritium = 12.3 years
Total mass pf tritium = 48.0 mg
Mass remain after 49.2 years = ?
Solution:
First of all we will calculate the number of half lives.
Number of half lives = T elapsed/ half life
Number of half lives = 49.2 years /12.3 years
Number of half lives = 4
Now we will calculate the amount left after 49.2 years.
At time zero 48.0 mg
At first half life = 48.0mg/2 = 24 mg
At second half life = 24mg/2 = 12 mg
At 3rd half life = 12 mg/2 = 6 mg
At 4th half life = 6mg/2 = 3mg
The amount left after 49.2 years is 3mg.
help i need help WITH this
Answer:
The Internet started in the 1960s as a way for government researchers to share information. ... This eventually led to the formation of the ARPANET (Advanced Research Projects Agency Network), the network that ultimately evolved into what we now know as the Internet.
(Please help I will give brainliest to whoever answers)Classify each of the following as either an element, compound, mechanical mixture, solution, colloid or suspension
a. Gold
b. Kool-aid
c. Carbon dioxide
d. Tomato juice
e. Milk
f. Salad
Answer:
element:a,c
compound:f
mechanical mixture
solution:b
colloid:e
suspension:d
Explanation:
what is the role identification of work performance
Explanation:
It is one of the most important factors that encourage workers to put forth great efforts and work more efficiently.
Not sure how to do these, one example would prolly help me do the rest
Answer:
3. a. I⁻
Explanation:
The charge of the ion is determined by which group (vertical on the periodic table) the element is in. Iodine is in the halogens and therefore is most likely to have a 1- charge.
Which action describes a chemical change?
A.) Crushing Rock
B.) Lighting a Match
C.) Freezing Water
D.) Melting Ice
Answer:
B
Explanation:
a chemical change is something that can not be reversed, so you may think crushing a rock but it isn't because crushing a rock is a phisical change not chemical and if you freeze water you can melt it and of you melt ice you can freeze it, so those can be reversed. So the answer is B because that can not be reversed
Since new substances are formed in chemical changes, Lighting a Match is a chemical change., option B.
What is a chemical change?A chemical change refers to a change which is not easily reversible and in which new substances are formed.
In chemical changes, large amounts of heat is involved and changes in the mass of the original substance may occur.
Examples of chemical changes are combustion of substances, oxidation of substances, etc.
From the given options, the change which involves great heat changes and in which new sure are formed is Lighting a match.
Therefore, Lighting a match describes a chemical change, option B.
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How does a balanced equation satisfy the Law of Conservation of Mass
Answer: I think d
Explanation: