Answer:
seal them in a glass container in an atmosphere of argon (Ar) gas
Explanation:
50 POINTS: PLEASE ANSWER AS QUICK AS POSSIBLE!
Question:
After getting their results in, a group of scientists went back and looked at their study. As planned, their experiment consisted of three groups. The first group received a new medicine at a normal dose, the second group received the medicine at half the dose, and the third group received the medicine at twice the dose.
Which of the following best describes what went wrong with the scientists’ study?
Choices:
- an improper experimental procedure
- the lack of a control group
- selection bias
- human error
Explanation:
The lack of a control group
6. Now, revise your definition for waves to include energy and matter.
A wave is a phenomenon that...
Answer:
A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.
Explanation:
A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.
There are two main types of waves Longitudinal waves travels parallel to their source. For example, sound waves. Through a series of rarefactions and compressions, longitudinal waves are propagated. Transverse waves travel perpendicular to their source.why is lithium used in the body?
Answer:
11
Explanation:
ultraviolet radiation has a higher frequency than visible light. which type of light wave carries more energy?
a=they carry the same amount of energy
b=visible light
c= ultraviolet radiation
Answer:
The answer to this question is C; ultraviolet radiation
Explanation:
The the reason for this is because it carries more energy per photon than visible light does. Light travels at a speed of 299,792 kilometers per second (about 186,282 miles per second).
What is the effect of tap water, sea water, and rainwater on the rusting rate of iron?
(Please i need an answer π-π)
Answer:
The more acidic the solution the faster it rusts. More Na = more rust
Explanation:
Which RNA strand would match with this DNA strand?
AGGCTAAT
What is the DNA strand? You have not named it.
Aquanauts explore the area called?
Answer:
Inner space
Explanation:
I hope this helps
Which phrase best describes igneous rocks?
form when lava and magma cool
accumulate sediments following erosion
require heat and pressure to be formed
consist of many sediment layers
ctivity
Answer:
A) form when lava and magma cool
please give me brainliest :p
God bless!
Answer:
A: form when lava and magma cools
Explanation:
Got it right on Edge 2020 :)
What is the relationship between the latitude and hours of daylight
Answer:
The tilt of the Earth's axis also defines the length of daylight.Daylight hours are shortest in each hemisphere winter. Between summer and winter
solistice the number of daylight hours decreases and the rate of decrease is larger the higher the latitude.The fewer sunlight hours the colder nights.
A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass
Answer:
Mass = 0.000176 gram
Steps:
m = V × ρ
= 20 milliliter × 8.8 gram/cubic meter
= 2.0E-5 cubic meter × 8.8 gram/cubic meter
= 0.000176 gram
Explanation:
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple center outlined in black with two concentric black circles around the center, the inner circle having 2 small green balls on it and the outer circle having 8 small green balls on it. What experimental evidence led scientists to change from the previous model to this one? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.
Answer:
B: The colors of light emitted from heated atoms had very specific energies.
Explanation:
dont know if its the same question i had on edg but i think its B. Sorry if i didnt understand the question :)
Answer:
b
Explanation:
Why is the nitrogen cycle considered a closed system?
Answer:
because nitrogen is fixed by bacteria and assimilated by plants
Explanation:
Answer:
It is a considered a closed system because nitrogen is fixed by bacteria and is taken in by plants.
Explanation:
The density of air at STP is 1.285 g/L. Which of the following cannot be used to fill a balloon that will float in air at STP?
NO can't be used to fill a balloon
Further explanationConditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
Answer options that need to be added :
a. Ne
b. NO
c. NH₃
d. CH₄
e. HF
will float in air ⇒ element or compound to fill the balloon, its density must be less than < 1.285 g/L
We can use the ideal gas formula ta find density :
[tex]\tt \rho=\dfrac{P.MW}{RT}[/tex]
Because at STP, then the constant value is
[tex]\tt \rho=\dfrac{1~atm\times MW}{0.08205\times 273.15~K}\\\\\rho=0.0446\times MW[/tex]
So that the density is determined from the MW(molecular weight) of each element or compound
a. NeAr = 20.1797 g/mol
[tex]\tt \rho=0.0446\times 20.1797=0.9~g/L[/tex]
b. NOMW=30.006 g/mol
[tex]\tt \rho=0.0446\times 30.006=\boxed{\bold{1.338~g/L}}[/tex]
c. NH₃MW=17.0306 g/mol
[tex]\tt \rho=0.0446\times 17.0306=0.760~g/L[/tex]
d. CH₄MW=16.04 g/mol
[tex]\tt \rho=0.0446\times 16.04=0.715~g/L[/tex]
e. HFMW=20.01 g/mol
[tex]\tt \rho=0.0446\times 20.01=0.892~g/L[/tex]
What’s this called please help
Answer:
the answer is a linear
Explanation:
heres a graph different ones at this link
Which is the IUPAC name for NO?
nitric oxide
binitrogen oxide
dinitrogen dioxide
nitrogen monoxide
The IUPAC name for NO is nitric oxide. The correct option is A.
What is IUPAC naming?The International Union of Pure and Applied Chemistry (IUPAC) is a global organization that represents chemistry as well as related sciences and technologies.
The chemical compound's identity is represented by its common and IUPAC names, which differ from one another. Every chemical compound has multiple names.
Complete the following step-by-step response: The IUPAC nomenclature is a standardized name given to organic compounds in accordance with official naming rules.
Nitric oxide, also known as NO, is a colorless gas. It is one of the most important nitrogen oxides.
Nitric oxide is a free radical, which means it has an unpaired electron, which is sometimes represented in its chemical formula by a dot.
Thus, the correct option is A.
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Answer:
D: Nitrogen Monoxide
Explanation:
There's one Nitrogen atom and one Oxygen atom
Elements in group to are cold alkaline earth metals what is most similar about alkaline earth metals how many protons and neutrons they have which Chemical properties he have how many total electrons they have which period They have most often found in
Answer:
explanations below
Explanation:
The alkaline earth metals are the 6 chemical elements that can be found in group two of the periodic table. These elements have a lot of properties in common, in the sense that they are generally shiny, reactive at standard temperature and pressure and they are also silvery-white. The elements are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra)
These metals have two electrons at their orbits, which can be easily lost to form cations (with charge +2, and an oxidation state of +2)
Below are some of their details
Name: Beryllium
Number of Protons/Electrons: 4
Number of Neutrons: 5
Name: Magnesium
Number of Protons/Electrons: 12
Number of Neutrons: 12
Name: Calcium
Number of Protons/Electrons: 20
Number of Neutrons: 20
Name: Strontium
Number of Protons/Electrons: 38
Number of Neutrons: 50
Name: Barium
Number of Protons/Electrons: 56
Number of Neutrons: 81
Name: Radium
Number of Protons/Electrons: 88
Number of Neutrons: 138
A cube of metal has a mass of 5.05 x 10°g and its density is known to be 12.77 g/mL, what is the volume of this metal?
A 395.5 mL
B. 2.529 mL
C. 63,910 mL
D. 64.48 ml
Answer:
Explanation:
option A is correct
Write the word equations for the following balanced chemical equations.
a. Zn + 2HCl → ZnCl2 + H2
b. 2503 2502 + O2
Answer:
21
Explanation:9+10
Identify the heterogeneous mixtures.
Group of answer choices
salad
water
vegetable soup
apple juice
trail mix
brass
You are about to take a short trip. However, you will not be traveling by car or bus; instead you will be traveling up in a hot air balloon. You know that hot air balloons, like the ones pictured, are able to rise when the air contained in them is heated. Why does the balloon rise? What is happening at the molecular level to make the balloon rise?
Answer:
Hot air rises. Heated air molecules “spread out” or expand and bounce around, and the space becomes less dense than the surrounding space. Increasing the air temperature inside the balloon envelope makes it less dense than the air, thus making it “lighter than air”.
Explanation:
I'm new to brainly but I hope this helped!
Balloon rise because Warm air ascends. Heat causes the molecules of the air to "spread out," or expand, and bounce off one another, making the area less dense than the surroundings.
What are molecules ?
A molecule is the smallest unit of a substance that keeps its content and properties. It is made up of two or more atoms that are joined together by chemical bonds.
Chemistry is built on molecules. The element symbol and a subscript indicating the number of atoms are used to identify molecules.
When Balloon rise because Warm air ascends. Heat causes the molecules of the air to "spread out," or expand, and bounce off one another, making the area less dense than the surroundings.
The air inside the balloon's envelope becomes less dense as the temperature rises, making it "lighter than air."
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what is 1.23 x 10^-3 in standard notation
Answer:
=0.00123
Explanation:
Look at the attachments below
Hope this helps (:
Answer:
0.00123
Explanation:
Standard notation is the normal way of writing numbers. Examples include 1, 2, and 10. The number 1.23 x 10^-3 is written in scientific notation. The decimal goes after the first nonzero integer and it is multiplied by a power of 10. The power or exponent attached to the 10 tells you how many places over you need to move the decimal to get back into scientific notation. Examples include 1.00 x 10^2 (representing 100 in standard form because you would move the decimal two places to the right.), 2.0 x 10^1 (representing 20 in standard form because you would move the decimal one place to the right), and 3.0 x 10^-4 (representing 0.0003 in standard form because you would move the decimal four places to the left since it is a negative exponent).
The negative (-3) exponent in 1.23 x 10^-3 indicated to move the decimal three places to the left. If it was positive, you would move it three places to the right.
In 1.23 x 10^-3 move the decimal to the left 1 place to get:
0.123
two places to get:
0.0123
and a third place to get:
0.00123
The final answer is 0.00123
what unit of measure would i use to measure the width of my fingernail A millimeters
B centimeters C meters D kilometers
E grams
25 POINTS
Boyd takes additional measurements of the mass of product formed in a reaction. He uses a balance that has smaller graduations than the first balance he used.
What is Boyd most likely trying to change?
Options:
He is trying to increase his accuracy but not his precision.
He is trying to increase his precision but not his accuracy.
He is trying to decrease his precision and increase his accuracy.
He is trying to increase his precision and decrease his accuracy.
Answer:
The correct option is A: "He is trying to increase his accuracy but not his precision"
Explanation:
Accuracy of measurement is when the value of the measurement is close to the actual value of that measurement while precision is when the experiment is repeated using the same instrument but obtaining different values.
When Boyd changed the weighing balance in his experiment to a smaller one, the smaller weighing balance has better accuracy (smaller graduations) than the initially used one because the smaller weighing balance will provide a value close to the actual value of the mass of the product. If he had, however, repeated the experiment without changing the weighing balance, he would have sought to increase his precision.
From the description above, it can be said that Boyd was trying to increase his accuracy but not his precision
Answer:
The correct option is A: "He is trying to increase his accuracy but not his precision"
Explanation:
right on EDGE 2021
A metal object has a density of 2 g/ml. When placed in a graduated cylinder with 500 ml of water, the
water rises to 508 ml. What is the mass of the metal object?
Answer:
The answer is 16 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
density = 2 g/ml
volume = final volume of water - initial volume of water
volume = 508 - 500 = 8 mL
We have
mass = 2 × 8
We have the final answer as
16 gHope this helps you
whats the lewis dot diagram for calcium
Draw the Lewis dot structure for each atom of the compound to show how many valence electrons are present in each atom. For example, the calcium atom in calcium chloride, CaCl2, has two valence electrons, and the chlorine atoms have seven valence electrons each.
Convert 122 moles of Methane to liters?
How many neutrons make up one of these potassium atoms?
Answer:
20
Explanation:
Answer question number 3
Answer:
A
Explanation:
A mixture is formed when two or more substances are physically mixed together. A compound is formed when two or more substances are chemically combined through a chemical reaction.
How many carbon atoms are there in 2.23 grams of propane (C3H8)?
Answer:
3.05x10²³ (3 sig. fig.)
Explanation:
Propane (C₃H₈) is a colorless alkane gas with three carbons and eight hydrogen atoms. In 2.23 grams of propane, there are 3.05 x 10²³ carbon atoms present.
What is the number of particles/atoms?
The number of atoms or the particles being the smallest units is estimated by the product of the number of moles and Avogadro's number.
The Avogadro's number (Na) is used to determine the number of particles that have been present in a mole of a substance. A mole of a substance is said to have 6.022 × 10²³ ions, atoms, electrons, molecules, etc.
Moles of propane are calculated as,
Moles = mass ÷ molar mass
= 2.23 ÷ 440.094
= 0.05057
Now, the number of particles is calculated as,
Number = moles × Avogadro's number
= 0.05057 × 6.022 × 10²³
= 3.05 x 10²³
Therefore, 3.05 x 10²³ carbon atoms are present in 2.23 grams of propane.
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How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight
Answer:
Explanation:
Noble gases are the least reactive of all known elements. That's because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.