Answer:
What are the Answer choices
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
The
force acting on an object is the combination of
all of the individual forces acting on it.
Check it
2 SCRATCHPAD
~ Improve this questio
Answer:
Yes as you can improve The invisible to human eye force or physical force if any being applied to a object of any mass and with all individual forces as they are acting on this object
Explanation:
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.Convert 122 moles of Methane to liters?
Which pair of symbols represents nuclei with the same number of neutrons?
A. 56 Co and 580
B. 57Co and 58Ni
c. 57Fe and 58 Ni
D. 57Mn and 57Fe
Answer:
B
Explanation:
Mass number = number of neutrons + number of protons
Atomic number is the number of protons in the nucleus.
58Ni : 58 is the number of neutrons + number of protons
atomic number of Ni is 28. Thus, 58 -28 = 30 neutrons
57Co ; 57 is the number of neutrons + number of protons
number of Co is 27. Thus, 57 – 27 = 30 neutrons
Aquanauts explore the area called?
Answer:
Inner space
Explanation:
I hope this helps
what does CER mean for science?
Explanation:
Claim, Evidence, Reasoning (CER) model, an explanation consists of: A claim that answers the question. Evidence from students' data. Reasoning that involves a rule or scientific principle that describes why the evidence supports the claim.
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
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]
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:
Refer to your periodic table:
Which of the following has the smallest atomic radius?
Bromine
Astatine
Iodine
Fluorine
iondine
Explanation:
bromine has 185pm, astatine haa 200, iondine has 140 and lastly fluorine has 147. so iondine has the smallest atomic radius
Which statement desrcribes an intensive property of matter? -it is the same for every sample of a single substance -it depends on how a substance was formed -it is the same for every sample of every substances -it depends on the amount of substances present
Answer:
The statement which describes an intensive property of matter is - :
it is the same for every sample of a single substance.
Explanation:
It is the same for every sample of a single substance. -: Since a substance 's intense property does not depend on either mass or volume, it is the same for each sample of a single substance. Hence , this statement is correct .It depends on how a substance was formed -: Intensive property do not depend upon the amount of the substance or the formation of the sample . Therefore this statement ifs wrong about intensive property .It is the same for every sample of every substances -: This is not possible to be for every sample of the substance , a every substance have different qualities. Hence this statement is also incorrect.it depends on the amount of substances present -: This is the characteristic of a extensive property of matter that relies on the amount of the material/substance. This assertion is, therefore, not valid.Hence , the correct option is A (it is the same for every sample of a single substance).
The diagram shows a model of an animal cell. Explain how you'd modify the model to show the structures in a plant cell.
Answer:to show the structures of a plant cell,add a cell wall around the membrane and increase the size of the vaculoe insidethe cell, draw green ovals to represent chloroplasts.
Explanation:
Identify the heterogeneous mixtures.
Group of answer choices
salad
water
vegetable soup
apple juice
trail mix
brass
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
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:
Which RNA strand would match with this DNA strand?
AGGCTAAT
What is the DNA strand? You have not named it.
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
What is hydrochloride acid plus water plus salt and water
What is the correct name for the compound P406?
A. Phosphoric acid
B. Tetraphosphorus hexoxide
C. Phosphorus (IV) oxide
D. Phosphorus oxide
Answer:
Phosphorus trioxide
Explanation:
Answer:
Tetraphosphorus hexoxide
Explanation:
Give brainliest please
I need help in chemistry!!!!!!!!!!!
Answer:
ok whats the question dude just ask :PPPPPPPPPPPPPPPPPPPPPP
OTHERWISE EOEOEEOEOEOOEOEOEOEOEOOEOWOWOWOWOW
wow is mom upide down
Explanation:
explanation of atomic radius
Ah yes.
The atomic radius is basically the distance between the nucleus of the atom and the outermost electron in the farthest orbital of the atom. The more bigger the atomic radius , the less powerful is the force that holds together the nucleus and its electrons.
What metal is Potassium (K)?
Explanation:
Potassium is a chemical element with the symbol K and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure
Answer:
alkali metalExplanation:
Potassium is a chemical element with symbol K and atomic number 19. Classified as an alkali metalHow 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.
Learn more about the number of particles/atoms here:
https://brainly.com/question/11884840
#SPJ2
why is lithium used in the body?
Answer:
11
Explanation:
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.
what unit of measure would i use to measure the width of my fingernail A millimeters
B centimeters C meters D kilometers
E grams
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
How many neutrons make up one of these potassium atoms?
Answer:
20
Explanation:
Two compounds of phosphorus and fluorine have the following
mass ratios.
Compound 1: 10.14 g fluorine for every 3.38 g phosphorus
Compound 2: 8.42 g fluorine for every 4.21 g phosphorus
Find the whole number ratio of masses of fluorine in compound
1 to compound 2.
Help me please
Answer: 3:2
Explanation: (10.14÷3.38)÷(8.42÷4.21)=1.5=3/2