Answer:what?
Explanation:what? Huh
Leon is creating a model using the items in the picture below. How could he best improve his model?
O
Earth
Moon
Sun
Make the earth larger than the sun
Make the moon larger than the sun
Make the sun smaller than the earth
Make the moon smaller than the earth
Make the moon smaller than the Earth.
How many molecules are contained in 125 grams of water, H20?
Answer:18.015 g
Explanation:
Water has a molar mass of 18.015 g/mol . This means that one mole of water molecules has a mass of 18.015 g . So, to sum this up, 6.022⋅1023 molecules of water will amount to 1 mole of water, which in turn will have a mass of 18.015 g
What unit is used to measure weight?
Answer:
The unit is: Newton.
Hope it helps:D
PLEASE HELP Will give brainliest and 50 points!! Please give honest answers
What is the mass of 0.55 mole
of magnesium chloride?
Answer:
SYMBOLS, FORMULAS AND MOLAR MASSES
OBJECTIVES
1. To correctly write and interpret chemical formulas
2. To calculate molecular weights from chemical formulas
3. To calculate moles from grams using chemical formulas
INTRODUCTION
Part I. Symbols and formulas
An element is a homogeneous pure substance made up of identical atoms. All matter is made
up of elements and, since chemistry is the study of matter, it is convenient to use symbols to represent
the elements rather than using the entire name.
By international agreement, specific symbols are assigned to each element (Note: This means
that while names of the elements vary with language, symbols are constant throughout the world.) Each
element is assigned a one- or two-letter symbol. The first letter is capitalized, the second (if there is
one) is not. While this often seems trivial, it is in fact a very important point. For example, in chemical
language Co represents cobalt, which is a metal and an element, while CO represents carbon monoxide,
a compound which is a colorless, odorless gas! Even when there is not an obvious correspondence,
for instance "MN", it can cause confusion. Do you mean the element manganese? Did you forget a
letter and mean something else? Are you using "M" to represent something else entirely? Chemists
sometimes use "M" to represent any metal. It is well worth the trouble to memorize the symbols for
common elements.
Since compounds consist of elements, the chemical formulas of compounds also consist of
elements with subscripts used to denote the number of atoms per molecule. If there is no subscript, it is
implied that there is one of that kind of atom. Ones never appear in chemical formulas. Not only do
subscripts denote ratios of atoms, they also denote the ratio of moles of element to one mole of
compound. Parentheses can be used to show groups of atoms, with the subscripts showing how many
groups there are. Parentheses are not used if there is only one group.
Examples: For one mole of the following compounds, how many moles of each element are
present?
MgCl2 1 mole Mg, 2 moles Cl
Mg(NO3)2 1 mole Mg, 2 moles N, 6 moles O
NaNO3 1 mole Na, 1 mole N, 3 mole O
AgCl 1 mole Ag, 1 mole ClPart II. Molar Masses
Each atom has a different size and therefore a different mass. The relative masses of each
element can be found on the periodic table. For example, one atom of magnesium weighs 24.31 amu
(atomic mass units). However, one mole of magnesium weighs 24.31 g. (Moles were planned that
way!) Since one mole of MgCl2 consists of one mole of magnesium and two moles of chlorine, the
mass of one mole of MgCl2 must be the sum of the masses of the elements. The mass of one mole of a
substance is called the molar mass or molecular weight.
Examples: What is the molar mass of the following compounds?
MgCl2 24.31 + 2(35.45) = 95.21 g/mol
Mg(NO3)2 24.31 + 2(14.01) + 6(16.00) = 148.33 g/mol
NaNO3 23.00 + 14.01 + 3(16.00) = 85.01 g/mol
AgCl 107.9 + 35.45 = 143.4 g/mol
(Note: Yes! You DO have to count significant figures when calculating molecular weight/molar
mass. However, the number of significant figures may vary depending on which periodic table you use.)
Chemists are generally interested in number of moles. Unfortunately, it is impossible to measure
moles directly. However, masses are easily measured, and if the chemical formula of the compound is
known, the molar mass can be used to determine the number of moles. The molar mass is defined as:
molar mass = grams/moles = g/mol (1)
Moles may be calculated by using molar mass as a conversion factor in dimensional analysis where
molar mass in grams = 1 (exactly) mole of compound (2)
This method is used in multi-step calculations. For example, if 0.873 g of MgCl2 is weighed out, it
is 9.17 x 10-3
moles.
1 mole
0.873g x 95.21 g = 9.17 x 10-3
mol MgCl2 (3)
However, 0.873 g of AgCl is only 6.09 x 10-3
mol.
1 mole
0.873g x 143.4 g = 6.09 x 10-3
mol AgCl (4)Molar mass may also be used to relate moles to grams. For example, 0.158 mol of MgCl2 is 15.2 g.
0.158 mol x 95.21 g = 15.2 g MgCl2 (5)
1 mol
Percent is used to express parts per one hundred. Usually in chemistry, it refers to
g of species of interest x 100 = % (6)
g of whole thing
Example: For the % Mg in MgCl2: In one mole of MgCl2, there are 24.31 g of Mg (molar mass of Mg,
the part we are interested in) and 95.21 g of MgCl2 (the whole thing), so %Mg in MgCl2 is
(24.31/95.21) x 100 = 25.53% Mg (7)
PROCEDURE
Work individually.
The formula for calcium phosphate is Ca3(PO4)2. Weigh about 2 g of calcium phosphate to the
nearest 0.001 g. In other words, you do not have to have exactly 2.000g, but you must know the
weight you have exactly. Acceptable results include but are not limited to: 1.985g , 2.035g, 2.314g
etc.
Be sure to report all results with the correct number of significant figures and appropriate units!
why sometimes the electrons of an atom transfer to higher energy level
Answer:
According to Bohr, the amount of energy needed to move an electron from one zone to another is a fixed, finite amount. ... The electron with its extra packet of energy becomes excited, and promptly moves out of its lower energy level and takes up a position in a higher energy level. This situation is unstable, however.
please answer this for me shehsh
Answer:
ih2706
Explanation:
Isotopes of the same element must have the same
A. atomic number
B. mass number
C. number of nucleons
D. number of neutrons
Answer:
D. number of neutrons
Explanation:
Isotopes of the same element must have the same number of neutrons. Neutrons of an atom are the uncharged particles within the nucleus.
Isotopy is the existence of two or more atoms of the same element having the same atomic number but having different mass number due to the differences in the number of neutrons in their various nuclei.
Therefore, isotopes differs based on the number of neutrons they contain.
Answer:
D. number of neutrons
Explanation:
Two isotopes of the same element have the same number of protons in the nucleus, but differ in the number of neutrons. The nucleon number is equal to the total number of protons and neutrons in the nucleus. ... The atomic mass number A is equal to the total number of protons and neutrons.
Help please!! I'll name you brainliest!!
Answer:
magesium di chloride
Explanation:
it has one magnesium and 2 chlorines
Answer:
Magnesium Chloride
Ethylene glycol (C2H6O2) is used as an antifreeze in cars. If 250 g of ethylene glycol is added to 3.00 kg of water, what is the molality? Calculate how much the freezing point of water will be lowered. The freezing-point depression constant for water is Kf = –1.86°C/m. Show your work.
Answer:
2,909 M
Explanation:
molair mass is of.ethylene is 26,04 g/mol
first you need to calculate how much mL 3 kg is. You can do this by using the density of ethylene: 1,1 g/mL.
3000 g x 1.1 = 3300 mL = 3,3 L
Next you need to calculate the amount of moles:
250 g / 26,04 g/mol = 9,60 mol
Now you can calculate the molarity:
9,6/3.3 = 2,909 M
I don't know the answer for the second question. I'm sorry.
Do the reactants or products contain more energy in the
decomposition reaction of sodium azide?
Answer:
reactants contain more energy in the decomposition reaction of sodium azide?
Explanation:
Is C6H1206 an element or compound
C6H1206 is a compound (of glucose).
WHICH VIRAL REPRODUCTION CYCLE HAD THE VIRUS PUTTING ITS GENETIC MATERIAL INTO THE CELL
A. lytic cycle
B. lysogenic cycle
C. both
What is the kinetic energy of a 9 kg object moving at a velocity of 5 m/s?
Find the volume of a locker that is 30cm long, 40cm wide, and 200 cm high.
Answer:
V= L × W × H so the answer is 240,000
If a balloon containing 3000 L of gas at 39°C and 99 kPa rises to an altitude where the pressure is 45.5 kPa and the temperature is 16°C,
the volume of the balloon under these new conditions would be calculated using the following conversion factor ratios:
( the one I have marked, I’m not sure if that’s the answer or not )
[tex]\tt =3000~L\times \dfrac{289}{312}\times \dfrac{99}{45.5}[/tex]
Further explanationGiven
3000 L of gas at 39°C and 99 kPa to 45.5 kPa and 16°C,
Required
the new volume
Solution
Combined with Boyle's law and Gay Lussac's law
[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]
T₁ = 39 + 273 = 312
T₂ = 16 + 273 = 289
Input the value :
V₂ = (P₁V₁.T₂)/(P₂.T₁)
V₂ = (99 x 3000 x 289)/(45.5 x 312)
or we can write it as:
V₂ = 3000 L x (289/312) x (99/45.5)
Question 5
Which of the following is not an example of mutualism?
The pressure of a sample of helium in a 200. ml. container is 2.0 atm. If the 5 points
helium is compressed toa volume of 10 ml without changing the
temperature, what would be the pressure of the gas? *
4000 atm
1000 atm
40 atm
0.1 atm
The pressure of the gas = 40 atm
Further explanationGiven
200 ml container
P = 2 atm
final volume = 10 ml
Required
Final pressure
Solution
Boyle's Law
At a fixed temperature, the gas volume is inversely proportional to the pressure applied
[tex]\tt \rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]
Input the value :
P₂ = P₁V₁/V₂
P₂ = 2 x 200 / 10
P₂ = 40 atm
As mass decreases, gravitational force ____
increase or decrease
How many atoms are in 4.72 moles or Ar?
Answer:
Argon is a chemical element with the symbol Ar and atomic number 18.
Explanation:
Answer:
Avogadro's number is a very important relationshiptoremember: 1 mole = 6.022×1023 6.022 × 1023atoms, molecules, protons, etc.
...
Explanation:
jayfeather friend me
Calculate the vapor pressure (in torr) of a 35°C solution of ethanol and propanol where the mole fraction of propanol is .75.
Assume ideal behavior.
P°ethanol = 100 torr
P°propanol = 36 torr
Answer:
i wish i know
Explanation:
The theory of _______ of matter states that cannot be created or destoryed
Word bank: Matter Volume Element Conservation Mass Atoms Properties
Answer:
mass pic is explanation hope it helps
Which statement below best describes the difference between an orbit and an orbital?
a. An orbit is a fixed path around the nucleus where an electron must be found; an orbital is a probability region where an electron is likely (but
not necessarily) going to be found
b. An orbit and an orbital are the same thing
c. An orbital is a fixed path around the nucleus where an electron must be found; an orbit is a probability region where an electron is likely (but
not necessarily) going to be found
Answer:
An orbit is a fixed path around the nucleus where an electron must be found; an orbital is a probability region where an electron is likely (but
not necessarily) going to be found
Explanation:
Orbits are fixed elliptical paths where an electron must be found. The idea of orbits was introduced in the Bohr model of the atom. Electrons were shown to occupy fixed orbitals of quantized energy.
Orbital is an idea introduced by quantum mechanics. It refers to a region in space where an electron may be found. The wave mechanical approach does not view the electron as being found in a fixed orbital but rather defines a region in space around the nucleus where there is a high probability of finding the electron.
Which of the following organisms would NOT be in the first trophic level of an energy pyramid?
A. dog
B. tree
C. algae
D. grass
The dog would not be in the part of first trophic level of an energy pyramid.
What is energy pyramid?Energy pyramid is defined as a model that show the flow of energy from one tropic or feeding level to next tropic or feeding level in an ecosystem.
There are basically three energy pyramid.
Pyramid of numberPyramid of biomassPyramid of energyTrophic level is defined as the source based on their nutrition or food, organisms occupy a specific place in a food chain.
First trophic level contains only green plants and producers. Their plants and product where consumed by second level of organisms.
Thus, the dog would not be in the part of first trophic level of an energy pyramid.
To learn more about energy pyramid, refer to the link below:
https://brainly.com/question/2837831
#SPJ5
Question 9(Multiple Choice Worth 1 points)
(05.03 LC)
Which of the following stars usually shine with the dimmest of light?
O Dwarfs
O Giants
O Main sequence stars
O Supergiants
How many grams of NH3 can be dissolved in 50 grams of water at 50oC?
15 grams of NH3 can be dissolved
Further explanationGiven
50 grams of water at 50°C
Required
mass of NH3
Solution
Solubility is the maximum amount of a substance that can dissolve in some solvents. Factors that affect solubility
1. Temperature: 2. Surface area: 3. Solvent type: 4. Stirring process:We can use solubility chart (attached) to determine the solubility of NH3 at 50°C
From the graph, we can see that the solubility of NH3 in 100 g of water at 50 C is 30 g
So that the solubility in 50 grams of water is:
= 50/100 x 30
= 15 grams
Which element has the larger ionization energy element E or Element M???
Answer: helium has the largest first ionization energy, while francium has one of the lowest.
Explanation:
The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.
Answer:
Helium has the highest
Explanation:
Is my answer correct?? Please correct me
Thank you!
Answer:
you are right
Explanation:
Which two subatomic particles have an equal, but opposite charge?
Answer:
Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite. Neutrons have no charge. Since opposite charges attract, protons and electrons attract each other.Hope that helps
Explanation:
Which of the following requires more energy then they produce?
Exothermic
Endothermic
(the subject is science but it wasn’t an option)
Answer:
The answer is endothermic