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
In preschool, students have the current exchange system for toys: 4 orange blocks = 5 stickers
7 stickers = 2 toy soldiers
3 toy soldiers = 6 dinosaurs
How many dinosaurs (dino) will a student get if they have 16 orange blocks?
Answer:
11
Explanation:
16 orange blocks = 4*5stickers
20 stickers=20*2/7 toy soldiers =40/7 toy soldiers
40/7 toy soldiers=40/7*6/3 dinosaurs =40*2/7=80/7 =11.43 ~~ 11 dinosaurs
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
What is ionization energy?
I am tryna make sure of my answer is this correct
Answer:
great job!!
Explanation:
ALL IS CORRECT :)
Michelle learns in science class that simple machines such as an inclined plane can change the amount of force needed to lift heavy objects. She decides to test this with an experiment.
Michelle chooses a 10 kg weight. She sets up a ramp made of smooth metal that makes an angle θ with the floor. She attaches a spring scale to the weight and the top of the ramp in order to hold the weight in place. She records the force from the spring scale, then changes θ and records it again. She repeats this several times.
In this experiment, what is the dependent variable?
A.
the mass of the weight
B.
the angle θ between the ramp and the ground
C.
the amount of force on the spring scale
D.
the material the ramp is made of
Be fast please
WILL MARK BRAINLIEST!!!! HELPPPP
what is the difference between simple distillation and fractional distillation
Answer:
A single distillation cycle is enough to separate the mixture. ... Simple distillation is the method used to separate substances in mixtures with significantly different boiling points, while fractional distillation is used for mixtures containing chemicals with boiling points close to each other.
Explanation:
Which materials sink in water? Hint: There is more than one nightanswer. Rubber Wooden Ball Ice Granite Titanium
Answer:
Granite and Titanium will sink
Explanation:
Granite and Titanium will sink in water.Granite and Titanium will sink in water because density of Granite and Titanium is higher then water. Also there raw shape does not help them to float on water.
1. The ability to dissolve in water and to conduct
electricity are examples of
a. physical properties.
b. chemical changes.
c. chemical properties.
d. chemical bonding.
Answer:
Physical
Explanation:
Because thats the answer
8. Which word best describes the element in box number 2?
a а Brittle
b Gas
С Semiconductor
d. Shiny
Answer:
gas
Explanation:
i think it might be gas
Which helps in the production of eggs?
Answer:
Feed Consistency.
Explanation:
Feeding that is supposed to yield the volume of a gnome for our chickens to lay eggs.
The Boxes of Clean Nests.
The Areas Free.
With calcium.
Regularly check it.
Protection Coop.
About fresh water.
Controlling Parasites.
Answer:
A. testosterone
Explanation:
i took the unit test
Ou are subliming camphor and you note that pure camphor is condensing nicely on the cold finger. You check on the process several minutes later and you see that the amount of camphor on the cold finger has not changed appreciably since the last time you looked at it. However, there is still plenty of impure camphor left at the bottom of the flask. What do you suppose is the reason and what do you need to do.
Answer:
The reaction is endothermic
Increase temperature of the flask
Explanation:
Sublimation is a phenomenon in which a substance changes directly from solid to gas,without passing through the liquid phase.
Camphor is a sublime substance. The sublimation of camphor is an endothermic reaction. This implies that energy is absorbed in the process.
For an endothermic reaction, the equilibrium position is shifted towards the right hand side by increasing the temperature of the system. Hence, if the flask is heated, more camphor will condense within a shorter time interval.
What do we call the molecule that forms when two atoms of the same element are covalently bonded to each other?
Answer:
Covalent Compounds and Diatomic Elements
Explanation: The two atoms that are held together by a covalent bond may be atoms of the same element or different elements. When atoms of different elements form covalent bonds, a new substance, called a covalent compound, results. Water is an example of a covalent compound.
Ore deposits contain high amounts of
A) water
B) volcanic magma
C) metals
D) minerals
The density of ice is 0.92 g/cm3 and the density of rubbing alcohol is 0.80 g/cm3. If an ice cube is placed in a container of rubbing alcohol, the ice cube will
Question 7 options:
a) float in the rubbing alcohol with none of the ice cube submerged.
b) sink to the bottom of the container.
c) move up and down in the rubbing alcohol.
d) float in the alcohol so that most of the ice cube is below the surface of the liquid.
Answer:
Option B. Sink to the bottom of the container.
Explanation:
From the question given above, the following data were obtained:
Density of ice = 0.92 g/cm³
Density of rubbing alcohol = 0.80 g/cm³
From the density of both substance given, we can see clearly that the ice has a higher density when compared with the rubbing alcohol.
Thus, If an ice cube is placed in a container of rubbing alcohol, the ice cube will not float rather, it will sink to the bottom of the container because the ice has a higher density than the rubbing alcohol.
what is the identity of the element that produced the unknown emission spectrum
Answer:
The emitted light can be observed as a series of colored lines with dark spaces in between; this series of colored lines is called a line or atomic spectra.
Explanation:
clarify the following expression s
a.atomic number
b.mass number
c.nucleus
Answer:
Atomic number of a chemical element is the number of protons found in the nucleus of every atom of that element.
The mass number, also called atomic mass number or nucleon number, is the total number of protons and neutrons in an atomic nucleus.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom.
Describe how evaporation relates to heat regulation in your body.
Which stage of the body's response to stress causes your body to try and restore
a state of balance, however sometimes causing pathological issues?
O Resistance Stage
"Fight or Flight"
"Alarm Stage"
O Recovery State
what property of matter describe how matter reacts with other matter ?
a.flammable
b.color
c.shape
d.volume
Answer:
Flammability
Explanation:
Flammability is a chemical property. So, this means that it must react with a substance.
Color, shape, and volume are physical traits. This means that no other matter needs to be included in order for this trait to be so.
3. In an exercise to teach students how to use and analytical balance, the instructor
gives a student a quarter which has been pre-weighed as 5.6026 g. The weight that the
student obtains for the same quarter is 5.6013 g. What is the percent error in the
students reading?
Answer:
The percent error is 0.023%.
Explanation:
Pre-weighed of a quarter is 5.6026 g.
The weight that the student obtains for the same quarter is 5.6013 g.
We need to find the percent error in the students reading. It is given by the formula as follows :
[tex]\%=\dfrac{|\text{original value-calculated value}|}{\text{original value}}\times 100[/tex]
Putting all the values, we get :
[tex]\%=\dfrac{5.6026 -5.6013 }{5.6026 }\times 100\\\\\%=0.023\%[/tex]
So, the percent error is 0.023%.
The cell membrane is found in all cells *
True
False
Answer:
true
Explanation:
all cells will have plasma membranes
What most accurately illustrates the electrostatic forces between protons and electrons?
What is the name of this ionic compound (Fr2SO4)
Answer:
3.5: Ionic Compounds- Formulas and Names
Last updatedAug 25, 2020
3.4: An Atomic-Level Perspective of Elements and Compounds
3.6: Molecular Compounds- Formulas and Names
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6.9: Binary Ionic Compounds and Their Properties
6.18: Ionic Compounds Containing Polyatomic Ions
Learning Objectives
Derive names for common types of inorganic compounds using a systematic approach
Nomenclature, a collection of rules for naming things, is important in science and in many other situations. This module describes an approach that is used to name simple ionic and molecular compounds, such as NaCl, CaCO3, and N2O4. The simplest of these are binary compounds, those containing only two elements, but we will also consider how to name ionic compounds containing polyatomic ions, and one specific, very important class of compounds known as acids (subsequent chapters in this text will focus on these compounds in great detail). We will limit our attention here to inorganic compounds, compounds that are composed principally of elements other than carbon, and will follow the nomenclature guidelines proposed by IUPAC. The rules for organic compounds, in which carbon is the principle element, will be treated in a later chapter on organic chemistry.
Ionic Compounds
To name an inorganic compound, we need to consider the answers to several questions. First, is the compound ionic or molecular? If the compound is ionic, does the metal form ions of only one type (fixed charge) or more than one type (variable charge)? Are the ions monatomic or polyatomic? If the compound is molecular, does it contain hydrogen? If so, does it also contain oxygen? From the answers we derive, we place the compound in an appropriate category and then name it accordingly.
Compounds Containing Only Monatomic Ions
The name of a binary compound containing monatomic ions consists of the name of the cation (the name of the metal) followed by the name of the anion (the name of the nonmetallic element with its ending replaced by the suffix –ide). Some examples are given in Table 3.5.2 .
Table 3.5.1 : Names of Some Ionic Compounds
NaCl, sodium chloride Na2O, sodium oxide
KBr, potassium bromide CdS, cadmium sulfide
CaI2, calcium iodide Mg3N2, magnesium nitride
CsF, cesium fluoride Ca3P2, calcium phosphide
LiCl, lithium chloride Al4C3, aluminum carbide
Compounds Containing Polyatomic Ions
Compounds containing polyatomic ions are named similarly to those containing only monatomic ions, except there is no need to change to an –ide ending, since the suffix is already present in the name of the anion. Examples are shown in Table 3.5.2 .
Table 3.5.2 : Names of Some Polyatomic Ionic Compounds
KC2H3O2, potassium acetate (NH4)Cl, ammonium chloride
NaHCO3, sodium bicarbonate CaSO4, calcium sulfate
Al2(CO3)3, aluminum carbonate Mg3(PO4)2, magnesium phosphate
Ionic Compounds in Your Cabinets
Ionic Compound Use
NaCl, sodium chloride ordinary table salt
KI, potassium iodide added to “iodized” salt for thyroid health
NaF, sodium fluoride ingredient in toothpaste
NaHCO3, sodium bicarbonate baking soda; used in cooking (and as antacid)
Na2CO3, sodium carbonate washing soda; used in cleaning agents
NaOCl, sodium hypochlorite active ingredient in household bleach
CaCO3 calcium carbonate ingredient in antacids
Mg(OH)2, magnesium hydroxide ingredient in antacids
Al(OH)3, aluminum hydroxide ingredient in antacids
NaOH, sodium hydroxide lye; used as drain cleaner
K3PO4, potassium phosphate food additive (many purposes)
MgSO4, magnesium sulfate added to purified water
Na2HPO4, sodium hydrogen phosphate anti-caking agent; used in powdered products
Na2SO3, sodium sulfite preservative
Table 3.5.3 : Names of Some Transition Metal Ionic Compounds
Transition Metal Ionic Compound Name
FeCl3 iron(III) chloride
Hg2O mercury(I) oxide
HgO mercury(II) oxide
Cu3(PO4)2 copper(II) phosphate
Naming Ionic Compounds
Name the following ionic compounds, which contain a metal that can have more than one ionic charge:
Fe2S3
CuSe
GaN
CrCl3
Ti2(SO4)3
Solution
The anions in these compounds have a fixed negative charge (S2−, Se2− , N3−, Cl−, and SO2−4 ), and the compounds must be neutral. Because the total number of positive charges in each compound must equal the total number of negative charges, the positive ions must be Fe3+, Cu2+, Ga3+, Cr4+, and Ti3+. These charges are used in the names of the metal ions:
iron(III) sulfide
copper(II) selenide
gallium(III) nitride
chromium(III) chloride
titanium(III) sulfate
Exercise 3.5.1
Write the formulas of the following ionic compounds:
(a) chromium(III) phosphide
(b) mercury(II) sulfide
(c) manganese(II) phosphate
(d) copper(I) oxide
(e) chromium(VI) fluoride
Answer
(a) CrP; (b) HgS; (c) Mn3(PO4)2; (d) Cu2O; (e) CrF6
Explanation:
The given compound is francium sulfate.
Explanation:
While naming ionic compounds :
First, write the name of cation Then after that name of the anion.Given
The molecule formula of a compound[tex]Fr_2SO_4[/tex]:
To find:
The name of the given compound formula
Solution:
Cation in formula = [tex]Fr^+[/tex] = Francium cation
Anion in the formula= [tex]SO_4^{-2}[/tex] = Sulfate anion
So, the name of the given compound is francium sulfate.
Learn more about the naming of compounds here:
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A bond between sulfur and oxygen would be what type of bond?
Answer:
Covalent Bond
Explanation:
Answer:
covalent bonding
Type of Bonding: Sulfur Dioxide is a process of covalent bonding, since Sulfur and Oxygen are both non-metals. The Sulfur is in the center surrounded by 2 Oxygen atoms. In this situation, as depicted below, Sulfur Dioxide is a resonance structure and can be expressed in three different forms
Explanation:
hope that helps
The speed of light in plastic is 2.0 x 108 m/s. Calculate the index of refraction for
plastic.
Answer:
n=c/v.
1.5=3×10^8/v
v=3×10^8/1.5
v=2×10^8 m/s
Hope this helps :)
The index of refraction for plastic, when speed of light in plastic is 1.5.
How do we calculate refraction index?Refraction index of any substance will be calculated by using the below equation:
n = c/v, where
c = speed of light in vaccum = 3×10⁸ m/s
v = speed of light in plastic = 2×10⁸ m/sec
On putting values in the above equation, we get
n = 3×10⁸ / 2×10⁸ = 1.5
Hence the refractive index of plastic is 1.5.
To know more about refractive index, visit the below link:
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The modern synthesis combined the concepts of _______ and evolution.
Answer:
genetics
hope this helps :)
Explanation:
Use the rules of significant figures to report the answer to this math question: (454.3 cL x 17.84 dL )/3.1 L =
Answer:
2614.423226
Explanation:
1.) Electromagnetic waves that you can see are called:
A) Ultraviolet rays
B) microwaves
C) visible light
D) infrared rays
2.) These waves have the longest wavelength and the lowest frequency.
A) infrared waves
B) radio waves
C) microwaves
D) gamma rays
3.) Which wave has high enough energy to cause damage to skin and sometimes cancer?
A) Ultraviolet rays
B) microwaves
C) visible light
D) infrared rays
4.) Waves with high frequency have a ___________ wavelength
5.)Electromagnetic waves are _________ waves, the energy of the wave moves at right angles to the direction of travel.
6.) Which type of wave travels faster in a vacuum: visible light or radio waves? Explain your answer.
7.) What Electromagnetic wave has the highest frequency? What does that mean about the energy of this type of wave?
8.) Mechanical waves like sound require a medium to travel. Are electromagnetic waves mechanical waves? Why or Why not?
9.) Identify each type of electromagnetic wave from the illustration.
(The photo comes with this question)
Lizzie is pushing Alex on a scooter. Lizzie is pushing with 75 N of force to the left,
and Alex is helping with 20 N to the left. What is the net force on the scooter?*
Answer:
95 N
Explanation:
they are both pushing in the same direction so you simply add
75+20=95