The control group are the students who eat no breakfast. The independent variable is the consumption of breakfast. The dependent variable is the performance of students in school.
In an experiment, the control group is the group that did not receive the treatment. The treatment in this case is the consumption of breakfast. Hence the group that did not consume breakfast is the control group.
The independent variable is the variable that is being manipulated and its effect evaluated. The manipulated variable here is consumption of food.
The dependent variable is the variable that is being measured. In this case, it is the performance of students at school.
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define mass number in your own words
Answer:
The total number of protons and neutrons in the nucleus of an atom is called mass number.
Answer:
mass number also called nucleon number and it's the total number of neutron and proton in an atomic nucleus.
In two atoms atom 'X' looses two electrons and atom 'Y' gains two electrons to form a compound 'XY'.Name the bond formed between X and Y.With two properties of the compound.
Please help me and i will mark you as brainleist.
Answer:
The bond formed between XY is "Ionic bond"
Explanation:
The bond is ionic bond because the compound XY is formed due to the gaining and loosing of electrons
Properties of Ionic compounds:
They form crystals
They are good insulators
They have high melting and boiling points
.
.
.
Hope it helps
If you burn a citronella candle near your picnic will it keep mosquitoes away
Answer:
Thanks!!!
Explanation:
Answer:
true
Explanation:
what happens to the food dye in hot water?
Answer:
The food coloring mixes through the hot water faster than it mixes with the cold water. The reason for this is because in hot water, the water molecules have more energy and are moving faster than the molecules of cold water. This makes it way more easier for the dye to get mixed throughout the hot water.
Explanation:
what is the concentration of hydrogen ion, H+, present in a water sample if 100. ml of the sample requires 7.2 ml of 2.5 x 10 -3 M NaOH to be neutralized
Answer: 1.8x10^-4 M H+
Explanation: The number of moles of NaOH added to the 100 ml soultion will be equal to the number of moles of H+ present in that solution.
Moles NaOH in 7.2 ml of 2.5x10^-3 M NaOH
(2.5x10^-3 M NaOH) is the same as 2.5x10^-3 moles NaOH/liter
(2.5x10^-3 moles NaOH/liter)*(7.2 ml)*(1 liter/1000ml) = 1.8x10^-4 moles NaOH used to titrate 100 ml of the acid. That means there was 1.8x10^-4 moles of H^+ in 100 ml.
Concentration of H^+ = (1.8x10^-4 moles H)/0.100 l) = 1.8x10^-4 M H+
(pH of 3.74)
How would you change the type of atom
Answer:
Hi, There! :)
If you change the number of protons an atom has, you change the type of element it is. If you change the number of neutrons an atom has, you make an isotope of that element.
Answer:
If you change the number of protons an atom has, you change the type of element it is. If you change the number of neutrons an atom has, you make an isotope of that element. All known elements are arranged on a chart called the Periodic Table of Elements.
Explanation:
that's what I found buddy
WHATS THE FREEZING POINT FOR WATER
Answer:
0 degrees Celcius and 32 degrees fahrenheit
Explanation:
Give an example of a non-biological chemical reaction that involves carbon. Name the process that converts a solid compound into a gas.
Answer: The combustion of methane (CH4) with O2.
Explanation: This is a chemical reaction involving carbon:
CH4 + 2O2 = CO2 + 2H2O
In the reaction 2H2 + O2 + H20, what coefficient should be placed in front of H2O to balance the reaction? 0 2 03 O 4
Answer:
2
Explanation:
2×2
2O
soooo
2H2O means 4H2O
A pan containing 20.0 grams of water was allowed to cool from a temperature of 95.0 °C. If the amount of heat released is 1,200 joules, what is the approximate final temperature of the water?
75 °C
78 °C
81 °C
87 °C
Answer:
81 °C
Explanation:
This is a calorimetry question so a few things you will need for this. The calorimetry equation q=mcΔT & the specific heat of water (4.2J/g•°C). Other definitions are:
q = heat added/released by a sample
m = mass of sample
c=specific heat of sample
ΔT = change in temperature
from here we can rearrange the equation to state:
q/(mc) = ΔT
1200J/((20.0g)(4.2J/g•°C)) = ΔT
14°C = ΔT
If the starting temperature was 95.0°C and we know that the temperature was cooled by 14°C then the final temperature of the water would be 81.
Answer:
C. 81 c
Explanation:
took the test :)
What is the approximate mass of one electron?
Answer:
9.1093837015 × 10^−31 kg
Very small mass
EASY 30 POINTS! PLS HELP ME T-T
1. True or false? All atoms in an element contain an identical number of neutrons.
2. An atom with a _______ charge has the same number of protons and electrons.
3. An atom that has a different number of electrons and protons is called a(n) _______.
Answer:
1.false
2.neutron
3.neutron
Answer:
1. false
2. zero
3. isotopes
hope it helps
Chemical changes can change which properties of a substance?
Group of answer choices
Reactivity
Color
Malleability
All of the above
Answer:
» Reactivity and color
Explanation:
though color is very minor answer because it also relates to a physical property.
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plss help :(((
What volume is indicated on each of the graduated cylinders below? The unit of volume is mL. Make sure to check the units of graduation to get the most accurate reading possible
Answer:
Explanation: The total volume (rock plus water) in the graduated cylinder is 34 mL. We know the volume of water in the cylinder was 20 mL. Therefore, the volume of the rock must be 14 mL. Because a milliliter is exactly the same volume as a cubic centimeter, the volume of the rock is 14 cm3.
Explanation:
Image result for The unit of volume is mL. Make sure to check the units of graduation to get the most accurate reading possible
Graduated cylinders have numbers on the side that help you determine the volume. Volume is measured in units called liters or fractions of liters called milliliters (ml).
Why do scientists use models of molecules?
A. To research the known effects of the molecule on the environment
B. To explain how electrons, protons, and neutrons are arranged
C. To show the structure of molecules, which are too small to see
D. To design an experimental setup to synthesize molecules
Answer:
C
Explanation:
Label each of the following 15 samples of matter as one of the following:
Sorry for the spamming, but this question is URGENT here,
Which of the following is
property of metals?
A. brittle
B. good conductivity."
C. poor conductivity
(Btw here’s a picture :O)
Option B, Metals have good conductivity.
Hope it helps you.. pls mark brainliest if it helps you
An atom of sodium-23 (Na-23) has a net charge of
+1. Identify the number of protons, neutrons, and
electrons in the atom. Then, explain how you
determined the number of each type of particle.
Use the
periodic table to help you.
Answer:
Protons= 11
neutrons= 12
electrons = 10
Explanantion:
Look for Na on periodic table
Atomic Number = 11
Atomic Mass = 23 (round it to be an integer)
Number of protons = Atomic number = 11
Number of neutrons = Atomic mass - atomic number = 23-11 =12
Number of electrons = 11 - e = ´+1 , electrons = 10
Answer:
Protons= 11
neutrons= 12
electrons = 10
Explanation:
That should be the answer :)
What effect does fermented sugar have in beer brewing
Answer:
If the sugar concentration level of the must becomes too high at any given point--either at the beginning or during the fermentation--it starts to have an inhibiting effect on the yeast's ability to produce alcohol. In other words, the higher sugar concentration starts to act as a preservative effecting the fermentation in a negative way.
Explanation:
Fermentation is the process by which yeast converts the glucose in the wort to ethyl alcohol and carbon dioxide gas -- giving the beer both its alcohol content and its carbonation.
Which of these are PHYSICAL changes?
А.
cutting, tearing, freezing, thawing, folding.
mixing without chemical changes
B.
burning, rusting, forming a new substance from
two different substances, exploding, cooking
Answer:
the answer to this problem is a
Freezing water cracking limestone
a
Chemical Change
b
Physical Change
Answer:
Freezing water and cracking limestone are physical changes.
surely help:) I’ll brainlist!
Answer:
A. The product formed have more energy than the reactants.
This is because it is an endothermic reaction.
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Plzzzzzz help me Write electronic configuratof sodium and chlorine in the term of subshell ?
Answer:
ans:Ne=2,8,1
ans:2,8,7
please answer quick...................
Answer:
3). C
Explanation:
When inter-nuclear distance [ atomic radius ] is smaller, the nuclear attraction has a greater magnitude.
[tex].[/tex]
what are the three formula of mole?
[tex] \huge \boxed{\mathfrak{Formulas} \downarrow}[/tex]
For all[tex] \large \sf \: mole = \frac{mass}{molar \: mass} \\ [/tex]
For gases[tex]\large \sf \:mole = \frac{volume}{molar \: volume} \\ [/tex]
For solutions[tex]\large \sf \:concentration \: ( \frac{g}{ {dm}^{3} } ) \\\large \sf \: = \frac{mass(g)}{volume( {dm}^{3} )} [/tex]
You can substitute mass with mole for concentration (mol/dm³).Which element would most likely lose electrons to form positive ions when bonding with other elements?
rubidium (Rb)
gallium (Ga)
argon (Ar)
iodine (I)
The correct answer to the question is Rubidium (Rb)
Rubidium (Rb) is a group 1 element and as such, it can form bond by losing it's valence electron (i.e 1 electron) easily.
Gallium (Ga) is a group 13 element. It can only form bond by losing it's 3 valence electrons.
Argon is a group 18 element. This group has completely filled outermost shell and are very stable. They do not involve in bond formation.
Iodine (I) is a group 17 element. It is more difficult for this group to lose its 7 valence electrons hence, they form bond by accepting 1 electron.
With the above information, we can conclude that Rubidium will most likely lose electron to form bond.
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Answer:
(Question 1)Which element would most likely lose electrons to form positive ions when bonding with other elements?
(Answer) rubidium (Rb)
(Question 2) Which statement about sodium chloride is correct?
(Answer) The sodium atom transfers electrons to the chlorine atoms to form ionic bonds.
(Question 3) Based on their locations in the periodic table, which two elements are most likely to form covalent bonds with each other?
(Answer) nitrogen (N) and oxygen (O)
(Question 4) Which phrase best describes electronegativity?
(Answer) the relative strength with which an element attracts electrons in a chemical bond
(Question 5) Based on the information in the table, which pair of elements would likely form the least polar bonds with each other?
(Answer) bromine and nitrogen
Explanation:
just finished the quick check enjoy UwU
Soot is formed as a candle burns
a
Chemical Change
b
Physical Change
Answer:
Chemical change
Explanation:
Because a new substance is formed.
(Physical Science)
Which group of metals includes elements with one valence electron? (1 point)
A. alkaline earth metals
B. rare earth metals
C. alkali metals
D. transition metals
Answer:
C
Explanation:
alkali metals are the Group I elements, which have 1 electron in their valence shells
Answer:
Alkali metals are the elements which have only one valence electron in their outermost or ultimate shell.
Explanation:
Alkaline Earth metals have 2 valence electron in their outermost shell and readily give up their 2 electron to achieve stability.
Rare Earth Metals have 3 valence electron in their outermost shell and they have high magnetic moments and divert range of magnetic structure.
Alkali Earth metals have 1 valence electron.
Transition metals generally have 2 valence electron .
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pls
answer
pls
pls
its ma homework
Answer:
2 ka A. nitrogen, oxygen, Carbon dioxide
Answer:
no 1 Ans gas
hope it works
underline and identify the parts of the text on this page that use examples of how the flow of the matter through a system is driven by energy and can do the work.
The parts of the text on the page that use examples of how the flow of matter through a system is energy driven and has the capacity to do work are;
1) The flow of water down rivers passing through hydro power dams to perform the following works;
River bank particle erosionElectric power generation2) The flow of electrons that corresponds to the flow of electricity (in the reverse direction) to perform the following works;
Light bulbs turn onTelevisions are powered3) The lifting of the hammer by the cam which gains gravitational potential energy that is converted to kinetic energy as the hammer drops
The hammer is repeatedly lifted and dropped by the cam to do the following work
Hammering a metal piece into shape4) The chemical potential energy stored in bonds by virtue of the relative atomic distances which produces kinetic energy from the chemical potential energy
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