Answer:
most developed nations.....
Explanation:
have more people and more resources to fix problems
The substances are placed in separate containers at room temperature, and each container is gradually cooled. Which of these substances will solidify before the temperature reaches 0°C?
Answer:
Benzene
Explanation:
it's freezing point is 5.5 C which is greater than 0 C
11. The respiration rate of a goldfish is
measured. The goldfish is then placed in
cold water and the respiration rate is
measured again.
Answer:
the respiration rate is the independent varaible ,measured is the indpendent variable i think
Explanation:
20. Convert: 7.7 mm
km.
a. 7.7 x 10-6
b.7.7 x 10-3
c. 7.7 x 103
d. 7.7 x 106
e. 7.7 x 102
1.) How do plants get their energy?
Answer:
Sun, water, caron dioxide.
Explanation:
They get there energy from those because photosynthesis the sun gives them that energy but the sun goes with water too because the sun and the water help it eat and produce its food and then the carbon is for it to breathe and thats how we have oxygen because the plants take in carbon and then they give out oxygen so thats why we need plants and plants need us.
Can i be brainliest.
which heat source would keep the pizza the warmest.
Answer:
a lot of heat source
Explanation:
In which chemical equation is the number of atoms in the reactants the same as the number of atoms in the products? A.Zn + 2HCl → H2 + ZnCl2 B.Li2CO3 → LiO + CO2 C. CO2 + H2O → CH2OH + O2 D. CH4 + O2 → CO2 + 2H2O
Answer:
A.
Explanation:
The chemical equation in which the number of atoms in the reactants is the same as that of products would be Zn + 2HCl → H2 + ZnCl2. The correct option would be A.
Let us consider all the component atoms in the equation: Zn + 2HCl → H2 + ZnCl2
Zn: 1 atom in the reactant side and 1 atom in product sideH: 2 atoms in reactant side and 2 in product sideCl2: 2 atoms in reactant side and 2 in product side.In Li2CO3 → LiO + CO2:
2 atoms of Li are in reactant side and only 1 in product sideIn CO2 + H2O → CH2OH + O2
2 atoms of H are in reactant side while 3 are in product sideIn CH4 + O2 → CO2 + 2H2O
Only 2 atoms of O are in reactant side while 4 are in product side.Hence, the only equation in which the number of atoms in the reactants is the same as that of products is Zn + 2HCl → H2 + ZnCl2
More on balancing chemical equations can be found here: https://brainly.com/question/21049751
2. Magnesium is an alkaline earth metal. With which group of elements is magnesium most reactive?
F. nonmetals
G. noble gases
H. alkali metals
J. transition metals
Answer:
alkali metals
Explanation:
alkali metals
The alkali metals, found in group 1 of the periodic table (formerly known as group IA), are very reactive metals that do not occur freely in nature. These metals have only one electron in their outer shell. Therefore, they are ready to lose that one electron in ionic bonding with other elements.
plz mark me as brainliest
1. 30 kg =___g
Idk how to do this pls help
Answer:
30000
Explanation:
all you have to do is multiply by 1000
Given a thin sheet of tin foil as shown below, determine the thickness of the foil if the mass is 1.68 g and the density of tin is 7.31 g/cm^3. Show all of your work. Round your final answer to two digits and don't forget units. (4 points) *PLEASE HURRY*
Given :
Mass of foil , m = 1.68 g .
Density of foil , [tex]\rho=7.31\ g/cm^3[/tex] .
To Find :
The thickness of the foil .
Solution :
Let , length and breadth is l and b respectively .
Also , height be h .
Volume is given by :
[tex]V=l\times b\times h[/tex]
Density is given by :
[tex]\rho=\dfrac{m}{V}\\\\V=\dfrac{m}{\rho}\\\\l\times b\times h=\dfrac{1.68}{7.31}\\\\l\times b\times h=0.23\\\\h=\dfrac{0.23}{lb}[/tex]
Therefore , thickness of the foil is [tex]\dfrac{0.23}{lb}[/tex] .
Hence , this is the required solution .
use the law of conservation of mass to complete this reaction. Na+Cl2
Answer:
sulfur, selenium, and oxygen.
Explanation:
I got it right on my test
Calculate the following using the correct significant digits: 3.10 x 4.520
Answer:
6
Explanation:
2+2=6
Answer:
3.10 × 4.520 = 14.0
Explanation:
Sig Figs
3
Decimals
1
Scientific Notation
1.40 × 10'
Brainliest! Please help me out with this table!! :(
Number of
Protons
Number of
Neutrons
Atomic
Number
Mass
Number
Element
(symbol)
20
20
А
B
С
9
D
E
19
F
Using the periodic table, complete the table to describe each atom. Type in your answers.
Answer:
A = 8
B = 8
C = O ( Oxygen )
D = 26
E = 30
F = Fe (Iron)
Explanation:
1)To get "A" we use the following formula
mass number = number of protons + number of. neutrons
15 = number of protons + 7
15 - 7 = number of protons
8 = number of protons
A = 8
2)To find "B"
atomic number = number of protons
Atomic number = 8
B = 8
3)To find "C"
the atomic number is 8 so the element which
has 8 atomic number on periodic table is Oxygen.
C = oxygen
4) To get "D"
Number of protons = atomic number
number of protons = 26
D = 26
5)To get "E"
mass number = number of protons + number of. neutrons
56 = 26 + number of neutrons
56 - 26 = number of neutrons
number of neutrons = 30
E = 30
6) To find "F"
The atomic number is 26 so the element which has 26 atomic number on periodic table is Iron.
hope it helps
for any question comment me ❤❤
Which element is in Group 17 and has more than 50 protons but less than 75 protons?
Answer:
Iodine
Explanation:
Iodine is in group 17 on the periodic table (first picture attached). The second picture shows you in the top left-hand corner of Iodine's little square, there is the number 53. This is the atomic number, it is also the number of protons and electrons in an element.
Hope this helped :)
3. SE7.12D The cell organelle responsible for providing energy for cell processes in plant
and animal cells is the -
A 5.32 g mixture contains both lithium fluoride, LiF, and potassium fluoride, KF. If the mixture contains 3.12 g fluorine, what is the mass of the KF in the mixture? mass of KF = _______ g Please only answer if you're going to answer seriously
Answer:
The mass of KF in the mixture is 2.77 gms.
Explanation:
Given;
Total weight of mixture (LiF+KF)=5.32gms
Let, mass of KF in the mixture = x gms
⟹ mass of LiF in mixture =(5.32-x)gms.
We know that :
Atomic weight of F=19gms.
Atomic weight of Li =7gms.
Atomic weight of K = 39 gms.
moles=mass/(molecular weight)
Thus, moles of KF=x/58
and moles of LiF = (5.97-x)/26LiF=(5.97−x)/26
Thus,
moles of F in KF=moles of KF=x/58 ---(1)
moles of F in LiF =moles of LiF= (5.32-x)/26---(2)
From (1) & (2),
Total moles of Fluorine
=(x/58)+((5.32-x)/26)
Hence,
total weight of Fluorine in sample = moles*Atomic weight
=((x/58)+((5.32-x)/26))*19gms.
=3.12 gms.---(given)
Now, solving the equation for x,
26x +(5.32*58)-58x
=3.12*58*26/19
22x=308.56-247.62
x=60.94/22
=2.77 gms. (Answer)
Thus, the mass of KF in the mixture is 2.77 gms.
What is 9872002 in scientific notation?
Answer:
= 9.872002 × 10^6
Explanation:
Move the decimal point in your number until there is only one non-zero digit to the left of the decimal point. The resulting decimal number is a.
Count how many places you moved the decimal point. This number is b.
If you moved the decimal to the left b is positive.
If you moved the decimal to the right b is negative.
If you did not need to move the decimal b = 0.
Write your scientific notation number as a x 10^b and read it as "a times 10 to the power of b."
Remove trailing 0's only if they were originally to the left of the decimal point.
If there are three naturally occurring isotopes of the hypothetical element R. The R-64 isotope has a 48.89% abundance and mass of 63.929 amu. The R-65 isotope has a 27.81% abundance and mass of 65.996 amu. The R-67 isotope has a 23.30% abundance and mass of 67.002 amu. Calculate the average atomic mass of the hypothetical element R.
Answer:
65.21g
Explanation:
[tex](48.89 \div 100) \times 63.929 = 31.25 \\ (27.81 \div 100) \times 65.996 = 18.35 \\ (23.3 \div 100) \times 67.002 = 15.61 \\ 31.25 + 18.35 + 15.61 = 65.21[/tex]
name physical properties
Answer:
Some examples of physical properties are:
color (intensive)
density (intensive)
volume (extensive)
mass (extensive)
boiling point (intensive): the temperature at which a substance boils.
melting point (intensive): the temperature at which a substance melts.
Explanation:
Hope this helped! <3
Material of density of 762 kg/m3 occupies a container
volume of 99 cm3. What is its mass?
Hint: density = mass/volume
Answer:
The answer is
0.075 kgExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
density = 762 kg/m³
We must first convert the volume from cm³ to m³
[tex]1 \: {cm}^{3} = 1 \times {10}^{ - 6} {m}^{3} [/tex]
So 99 cm³ will be
[tex]9.9 \times {10 }^{ - 5} \: \: {m}^{3} [/tex]
So the mass of the material is
[tex]mass = 762 \times 9.9 \times {10}^{ - 5} \\ = 0.075438[/tex]
We have the final answer as
0.075 kgHope this helps you
Answer:
75438 kg
Explanation:
According to Dalton’s atomic theory, atoms:
A.are destroyed in chemical reactions.
B.can be divided.
C.of each element are identical in size, mass, and other properties.
D.of different elements cannot combine
Answer:
C
Explanation:
Dalton's atomic theory are: Everything is composed of atoms, which are the indivisible building blocks of matter and cannot be destroyed. All atoms of an element are identical. The atoms of different elements vary in size and mass.
Dalton's atomic theory opines that atoms of the same element are identical in size, mass, and other properties and are different from atoms of other elements.
In addition, Dalton theorized that atoms can neither be created nor destroyed, and they are the smallest indivisible particle of elements.
He also proposed that atoms of different elements are also able to combine in whole number ratio to form compounds.
More on Dalton's atomic theory can be found here: https://brainly.com/question/13157325?referrer=searchResults
the precautions that must be taken when carrying out experiments with hydrogen gas
Explanation:
Never smoke near a place where hydrogen is generated or being used. Remove all possible sources of flame and sparks. Hydrogen should only be generated and used in a well ventilated out door area. Precautions must be taken to remove all possibilities of fire or explosion.
A science class is conducting an experiment that produces noxious fumes. Because of inadequate ventilation, some students begin to feel nauseated and dizzy. The first response should be to
To solve this we must be knowing each and every concept related to experiment. Therefore, the correct option is option A that is to leave the room and go to an area with fresh air.
What is experiment?Any procedure where measurements are taken and tests are run to support or disprove a hypothesis is referred to as a scientific experiment.
A science class is conducting an experiment that produces noxious fumes. Because of inadequate ventilation, some students begin to feel nauseated and dizzy. The first response should be to leave the room and go to an area with fresh air.
Therefore, the correct option is option A that is to leave the room and go to an area with fresh air.
To learn more about experiment, here:
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Which of the following substances is used up during photosynthesis?
In Rutherford's experiment, when particles strike the
zinc sulfide screen, they produce flashes of light or
scintillations which can be detected.
A-Gamma
b -Meson
C-Beta
d Alpha
Answer: D- Alpha
Explanation:
A coyote and an oak tree both have DNA?
Answer:
true, they both have different types of DNA.
Answer:
Um yes... they have different DNA's.. ;-;
Explanation:
3. The dry air in the Alps helped to prevent damage to the cells in the Iceman's body.
(1 Point)
true
false
is this true or false ?
Answer:
False
Explanation:
because they do not prevent damage they make damage
a 20.0g sample of an element contains 2.16x10^23 atoms identify the element
Answer:
yes
Explanation:
round 0.000789 to 2 significant figures
Answer:
0.00079
Explanation:
Any zero after the decimal isn’t a significant figure
How is this model useful?
O It shows how electrons are distributed in the shells of an iron atom.
O It shows how electrons are distributed in the shells of a cobalt atom.
o It shows how orbitals are distributed in the shells of an iron atom.
It shows how orbitals are distributed in the shells of a cobalt atom.
Answer:
A) It shows how electrons are distributed in the Shells of an Iron atom.
Explanation: Took the test on Edge
To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option A.
What is atom?Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.
In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. The given model shows how electrons are distributed in the shells of an iron atom.
Therefore, the correct option is option A.
To know more about atom, here:
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