find the product of (x+a)(x-a)
Answer:
x^2 - a^2
Explanation:
The total pressure of a mixture of hydrogen, oxygen, and methane is 96.4 kPa. The partial pressures of hydrogen and oxygen are 13.5
kPa and 29.3 kPa respectively. What is the partial pressure of methane?
A. 139.2 kPa
B. 53.6 kPa
C. 82.9 kPa
D. 42.8 kPa
Answer:
53.7kPa
Explanation:
Given parameters:
Total pressure of the mixture = 96.4kPa
partial pressure of hydrogen = 13.4kPa
partial pressure of oxygen = 29.3kPa
Unknown:
partial pressure of methane = ?
Solution:
The total pressure of mixture is equal to the sum of their particles pressures;
Partial pressure of methane = 96.4kPa - (13.4kPa + 29.3kPa)
Partial pressure of methane = 53.7kPa
Answer: 53.6
Explanation: I just took the test and got it right.
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:
How far does a car travel in 0.75 hr if it is moving at a constant speed of 88km/hr?
Answer:
66 km.
Explanation:
88 km / 1 hour = 66 km / 0.75 hours.
You need to just multiply 0.75 by 88.
The answer is 66 km.
1.State the relationship between the following properties:
a) mass and number of moles__________
b) number of moles and number of particles __________
6. Show how you will compute for the number of particles given the following:
a) Mass of the sample__________
b) Number of moles of the sample__________
Thankyouu po sana my mag answer
Answer:
bytbyufvguv vvg uggy yvgu vgu gyu7yng8ugng88yn
A doctor prescribes 125 mg of penicillan to be taken 4 times each day. The
concentration of the solution given to the patient is 250mg penicillan/5ml. How
many mL should the patient take in each dose?
1) 500 mL
2) 10.0 mL
3) 2.50mL
4) 50.0 mL
5) 2.0 mL
10 ml should the patient take in each dose
Further explanationGiven
125 mg of penicillan ⇒ 4 times/day
The concentration = 250 mg/5 ml
Required
The volume of the dose
Solution
The mass of penicillan/day :
= 125 mg x 4 times
= 500 mg
The volume/day :
= 500 mg : 250 mg/5 ml
= 10 ml
Help thanks thanks thanks
Answer:
the answer is (G)
Explanation:
It is G!
Your welcome!
Need help plz!
-Which property describes a mixture?-
A. It cannot be separated by physical methods.
B. It has a single chemical composition.
C. It cannot have more than one state of matter.
D. It cannot be described by a chemical symbol or formula.
Answer:
D as a mixture is not a compound and it does not have it's own chemical formula
Explanation: Sauce me brainliest
It cannot be described by a chemical symbol or formula.
- Chilio
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)
what kind of substance is rust
1.
What is the light that you can see called?
VED
DANCE
WOW
EN
M
W
NOGO
OLET
a) observatory light
c) visible light
b) ultraviolet light
d) infrared light
Answer:
The correct answer is c. Your welcome
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!
What does the large number in front of
the molecule represent?
lons form when atoms gain or lose valence electrons. When an atom gains
electrons, it becomes negatively charged, and when an atom loses
electrons it becomes positively charged. Why?
Answer:
In neutral atom number of electrons (negativity charged particle) and number of proton ( positively charged particle) are equal.
When one or more electrons are lost so positive charge particle increases and cation is formed.
For example in Na 11 electrons and 11 protons are present when it loses one electrons protons are 11 and 10 electron are remaining so one positive charge is present.
Morever when an element gain electrons one negative charge increases and anion is formed. For example in Cl 17 proton and 17 electrons are present when it gain one electron 18 electrons and 17 protons are now present one negative is more so anion negative ion is formed.
Explanation:
Graphite has a specific heat of 0.709 J/gºC. If a 25 gram piece of graphite is cooled
by 17°C, how much energy was lost by the graphite?
Answer:
[tex]\boxed {\boxed {\sf 301.325 \ Joules }}[/tex]
Explanation:
Since we are given the mass, specific heat, and change in temperature, we should use this formula for energy:
[tex]q=mc \Delta T[/tex]
The mass of the graphite is 25 grams. Graphite's specific heat is 0.709 J/g °C. The change in temperature is 17 degrees Celsius.
[tex]m= 25 \ g \\c= 0.709 \ J/g \ \textdegree C \\\Delta T= 17 \ \textdegree C[/tex]
Substitute the values into the formula.
[tex]q= (25 \ g)( 0.709 \ J/g \ \textdegree C )( 17 \ \textdegree C)[/tex]
Multiply the first two numbers. The grams will cancel.
[tex]q= 17.725 \ J/ \textdegree C(17 \ \textdegree C)[/tex]
Multiply again. This time the degrees Celsius cancel.
[tex]q= 301.325 \ J[/tex]
The graphite loses 301.325 Joules of energy.
Why did Mendeleyev try to reorganize the periodic table?
How many moles of a gas sample are in a 5.0 L container at 373 K and 203 kPa?
0.33 mole
0.66 mole
1.11 moles
3.05 moles
Answer:0.33
I'm not sure tho
Answer:
0.33
I just took the test.
One of the main jobs of _________ is to support the leaves
The flowers
the seeds
the roots
the stem
Answer:
Stem
Explanation:
Answer:
option-(d) stem
Explanation:
Stems have four main functions which are: Support for and the elevation of leaves, flowers and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits. Transport of fluids between the roots and the shoots in the xylem and phloem...
I hope it help you
As mass decreases, gravitational force ____
increase or decrease
what is the name for a change in the environment that causes an organism to change it's activity
Answer:
the answer is stimilus!
Explanation:
CuSO4 +
KI →
Cul +
12 +
K2SO4
kind of protists can live in groups with different individuals performing different jobs (site 1)
Answer:
The plasmodial slime molds are the kind of protist that can live in groups in which different individuals perform different jobs. Some kinds of bacterial cell walls also have other functions.
How would a flood impact an ecosystem?
Loss of life
Displacing organisms' habitats
Polluting bodies of water as the floodwater recedes
All answers are correct
UPDATE: Just took the quiz the answer is D. All of them.
Answer:
all of them
Explanation:
took test
Floods can cause soil erosion and sedimentation. It will destroy all the properties of human beings. All the options are correct. Thus the correct option is D.
What is Flood?Flood is defined as a natural disaster which results from the overflow of water on land. It is mainly generated by the heavy rainfall, sudden snow melt, etc. It affect the ecosystem adversely.
The floods are mostly affected to the coastal regions. It is even a threat to life of people. The habitat of aquatic organisms are destructed by the floods. The ground water is found to be contaminated with pathogenic microbes and causes water borne diseases.
As a result of floods the life of small insects which play a primary role in the ecosystem of food chain is also affected. All fields like education, communication, transport, etc. of our state is affected by the floods.
The floods can cause loss of people, low water quality, destruction of habitats. Some times the effect of flood in our life will be long lasting.
Thus the correct option is D.
To know more about Flood, visit;
https://brainly.com/question/28725721
#SPJ6
Why can single bonds rotate freely?
Please help me :D I’m begging rn lol
Answer:
To catch a ball, the fielder has to stop the ball. This means, force is applied against the motion of the ball. So, between the fielder applies force on the ball and the ball comes to rest, the ball moves in the direction opposite to the direction of force. Thus work is negative.
Explanation:
MARK ME AS BRAINLIEST PLSSS
Omg please help me im doing so well in science i have a 100 and this if for a grade and i really need t o kkeep that 100
Answer:
b
Explanation:
This means that it takes more energy or heat to increase water's temperature than it does for most other substances. The specific heat of water is greater than that of dry soil, therefore water both absorbs and releases heat more slowly than land.
True/False: All of the elements combine in a variety of ways to make up all living and all nonliving things
Answer:
true
Explanation:
Is energy part of the system or surrounding?
Answer:
Se Puede Traducir?
Explanation:
Mmm?
Answer:
i think it is surroundings
Calculate the atomic mass of oxygen if the three common isotopes of oxygen have masses of 15.995 amu (99.759% abundance), 16.995 amu (0.037 % abundance), and 17.999 amu (0.204 % abundance).
Answer:
16 amu
Explanation:
PLEASE HELP!!!!!!!!!!!!!!!!!!!! ASAP!!!!!!!!! Which two elements are mainly found in the inner and outer core?
A. Fe and Ni
B. Fe and Si
C. Ni and Si
D. Ni and C
PLEASE TELL ME WHAT THOSE ABREVIATIONS MEAN ALSO!!!!!!!!!!!!!