Answer:
Because we are not perfect
Explanation:
This day is added to the calendar as a corrective measure, because the Earth does not orbit the sun in precisely 365 days.
find the percent composition of lead in lead (II) nitrate. round to 2 significant figures.
Answer/Explanation:
62.559%
mass of an element X 100%
mass of the compound
Scientific Notation: 3.45 x 10^5
E Notation: 3.45e5
How many moles of butane (C4H10(g)) were combusted in the presence of excess
oxygen gas if 55.8 L of water vapour at STP is collected?
Moles of Butane combusted : 0.4982
Further explanationGiven
55.8 water vapour at STP
Required
moles of Butane
Solution
Reaction(Combustion of Butane) :
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
1 mol at STP = 22.4 L, so mol of H₂O for 55.8 L :
=55.8 : 22.4
=2.491 moles
mol H₂O based on Butane as a limiting reactant(excess Oxygen)
From the equation, mol ratio Butane-C₄H₁₀ : H₂O = 2 : 10, so mol Butane :
[tex]\tt =\dfrac{2}{10}\times 2.491\\\\=0.4982[/tex]
Density can be calculated by dividing an object's mass by its volume. If the mass of an object is 10 grams and its volume is 2 milliliters, what is its density?
Explanation:
mass =10g. volume=2ml. density=mass/volume = 10/2=5kg/m^3Answer:
5 g/mL
Explanation:
So, if the mass is 10 g and the volume is 2 mL, the density equals...
10 g ÷ 2 mL = 5 g/mL
State and explain each law of motion.
Answer:In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction
Explanation:
Answer:
EEEEEeeEEeEEEEEEEeEEEEEEEEEE
Explanation:
e
Significant Figures
1. Indicate how many significant figures there are in cach of the following measured values.
un
246.32
5
1.008
700000
107.854
3
0.00340
3
350.670
4
100.3
14.600
1.0000
6
0.678
0.0001
320001
Please help
mg(oh)2
How many H atoms are there?
How many Mg?
What is the total number of atoms?
Answer:
There are 2 hydrogen atoms, one magnesium atom, and 5 atoms in total.
Explanation:
We are given a compound in formula form. To make things easier to understand, we can first convert this to the name of the compound.
When a compound contains one or more elements in parentheses, these are usually a polyatomic ion. Polyatomic ions are ions made up of two or more elements with a positive or negative charge over the entire ion. Commons examples of these NH₄⁺ (ammonia) and HCO₃⁻ (bicarbonate). You can combine metals with polyatomic ions to create commonly known compounds, such as baking soda. The chemical name for baking soda is sodium bicarbonate, so we can combine Na (sodium) with HCO₃⁻ (bicarbonate) and create sodium bicarbonate: NaHCO₃.This compound is one magnesium atom bonded to two hydroxide ions.
Hydroxide is the compound between one hydrogen atom and one oxygen atom. The compound overall adopts a negative charge of 1.If we have one hydrogen atom and one oxygen atom, the most electronegative atom is written first in chemical formulas. Therefore, the symbol for Oxygen (O) goes first.Then, write in the hydrogen atom directly after the O symbol: OH.Finally, since we have a negative charge on the ion, we need to play a negative sign as a superscript for the compound. Therefore, this becomes OH⁻.Now, we need to determine the charge on the Magnesium atom which is determined from the amount of valence electrons the atom has.
On a periodic table, the symbol for Magnesium is Mg and this element has 2 valence electrons. In order to fulfill the Octet Rule, the It is more likely to give up 2 electrons to a nonmetal than it is to gain 6, so we can safely assume that the charge is ²⁺.We need to use the criss-cross technique to transfer the charges between the element and the ion, so the negative 1 charge goes to the Mg, which does not appear (negative 1 or positive 1 are implied) and since the magnesium has a charge of positive 2, this is the subscript for the hydroxide ion.Therefore, our compound becomes Mg(OH)₂, and we have labeled this as magnesium hydroxide.Now, to the number of atoms:
The new charge on Mg is 1-, so there is only one atom of Mg.The charge is 2+ on the OH ion, so there are two atoms of H and two atoms of O.Two atoms of oxygen, two atoms of hydrogen, and one atom of magnesium add up to be five atoms in total.PLEEEASSEEEE HELPPPPP!!!!!Take some time to research a utility plant. If there is one in your area, you may even visit it.
Otherwise, look up a type of plant that produces energy - such as a nuclear power plant, a
hydroelectric plant, or a coal-burning plant. Find out what energy resources are brought into the
plant. Then find out what energy and what "waste" is produced by the plant. Describe how the
two Laws of Thermodynamics apply to what you find out in your research. Be thorough. You will
be using the information you gather to engage in a debate with your class about
thermodynamics.
Answer:
There are four laws of thermodynamics that define fundamental physical quantities (temperature, energy, and entropy) and that characterize thermodynamic systems at thermal equilibrium.
Explanation:
teachers instructions - “ clear my examples and replace with your own words “ you get brainliest if I get good grade :)
Answer:
can you give me more clearence on what is going on
Explanation:
HELP!!! ASAP!!!! WILL MARK BRAINLIEST!!!!
A certain covalent compound contains sulfur bonded to chlorine. Which of the following statements about this compound is correct?
Question 5 options:
A)
Electrons will reside closer to sulfur, and the bond will be non-polar.
B)
Electrons will reside closer to sulfur, and the bond will be polar.
C)
Electrons will reside closer to chlorine, and the bond will be polar.
D)
Electrons will reside closer to chlorine, and the bond will be non-polar.
Answer:
C) Electrons will reside closer to chlorine, and the bond will be polar
Explanation:
Electrons tend to be closer or attracted to high electronegativity and sulfur has less electronegativity than chlorine. Therefore, electrons will reside closer to chlorine. To find out if it is polar or nonpolar, according to the electronegativity chart you can find online, you can see that the electronegativity of sulfur is 2.5 while the electronegativity of chlorine is 3.0. Because the difference between these two is a slight change, it would be slightly polar. So, the bond will be polar.
Answer:
Electrons will reside closer to chlorine, and the bond will be polar.
Explanation:
PLEASE HELP I'M BEING TIMED!! Which type of star system has the most stars?
A. Open Cluster
B. globular cluster
C. Eclipsing binary
D. binary star system
Answer:
Hi! It's B - globular cluster
Answer:
B Globular Cluster
Explanation:
Sorry if I am wrong :)
what is chemistry?
in your own word please 2-3 sentence
Answer:
the science that deals with the properties, composition, and structure of substances they undergo, and the energy that is released or absorbed during these processes.
Explanation:
Answer:
Is the scientific branch that deals with the composition and decomposition of elements and compounds in nature
(60 points + brain list) The correct electron configuration of the O2-ion is
A)
2-4
B)
2-5
C)
2-7
D)
2-8
explain with example the combination and decomposition reaction.
Answer:
Decomposition reactions require an input of some form of energy. For example, under the influence of an electric field, water breaks down to give hydrogen and oxygen. In the presence of sunlight, hydrogen peroxide decomposes into oxygen and water.
What is depicted in a molecular formula?
Answer:
Molecular formula describes about number of atoms of each constituent element present in any molecule.
Explanation:
Molecular formula describe about the number and type of atoms in any molecule. A molecular formula is not a chemical name but instead it is a chemical formula of a compound. A molecular formula consist of chemical symbols for constituent elements followed by numeric subscripts which tells us about number of atoms of each element present in a molecule. For example : Ammonia is a compound of nitrogen and hydrogen i.e NH₃ . As there is only one N atom so we have written only N in it's molecular formula. But as there are 3-H atoms so we have written subscript 3 in H symbol in it's molecular formula. Molecular formula does not tell us anything about shape of molecule .
2C3H7OH + 9O2 --> 6CO2 + 8H2O
Determine the number of grams of CO2 produced from the reaction of 5.55 moles of C3H7OH?
a
1466 g
b
16.7 g
c
367 g
d
12.2 g
e
733 g
Please show work
Answer 12.2g is the answer
Can you please help me ASAP
Answer:
The Milky Way is a large barred spiral galaxy
Explanation: that has more than etc
which rock is the result of changes on the Earth's surface?
igneous rock
sedimentary rock
metamorphic rock
Answer:
metamorphic
Explanation:
when one rock changes another rock the rock that got changed is now metamorphic
Identify the following as a chemical (C) or physical property (P):
1. blue color ______
2. melting point ______
3. density ______
4. reacts with water ______
5. flammability (burns) ______
6. solubility (dissolves) ______
7. boiling point ______
8. luster ______
Answer: 1. Phys 2. Phys 3. Phys 4. Chem 5. Chem 6. Phys 7. Phys 8. Phys
Explanation:
According to the concept of physical and chemical property ,reaction with water and flammability are chemical properties while rest are physical properties.
What are chemical properties?These properties are defined as those properties which become evident during or after a chemical reaction after the identity of the substance is changed during chemical reaction.
These properties cannot be determined externally just by viewing the substance ,these change immensely after a substance undergoes a chemical change.These are used for identification of unknown substances and for building up chemical classifications.
The major chemical properties are flammability,toxicity,reactivity,acidity and heat of combustion.For a chemical property to be apparent , it is necessary that the structure of the substance is altered.
Learn more about chemical properties,here:
https://brainly.com/question/5186976
#SPJ2
Please help!! This would mean so much to me!!
Answer:
I think it's the A one. Hope it's correct
Answer:
A option is correct
Explanation:
when 45mL of 0.25mol/L sulfuric acid is mixed w/ 25mL of 0.58mol/L Calcium hydroxide, the solution has a?
Which of the following equations represents the balanced equation for the reaction of iron and oxygen?
a)
4Fe + 3O2 → 2Fe2O3
b)
2Fe + O2 → Fe2O3
c)
3Fe + 3O2 → 2Fe2O3
d)
Fe + 3O2 → Fe2O3
Answer:
D is balanced. :)
Among the following equations the one that represents the balanced equation for the reaction of iron and oxygen is a.
4Fe + 3O₂ → 2Fe₂O₃
What is balancing of a reaction?Balancing of a reaction is done according to the "Law of conservation of mass" and balancing helps in solving stoichiometry questions correctly as if we will not balance the reaction then the quantitative results in a particular question doesn't come correctly.
Balancing of a reaction helps in mole concept as well and it is one of the laws of chemical reactions as well.
Some examples of balanced chemical reactions are-
2Mg(s) + O₂(g) ⟶ 2MgO(g)
Ca(OH)₂ + H₃PO₄ → Ca₃(PO₄)₂ + H₂O
Therefore, Among the following equations the one that represents the balanced equation for the reaction of iron and oxygen is a.
4Fe + 3O₂ → 2Fe₂O₃
Learn more about Balancing of a reaction here:
https://brainly.com/question/14280002
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scientific notation, fill in the blank.
7.95x10^7 = [ ? ]x 10^6
Answer:
79.5
Explanation:
7.95x10^7 IS 79500000.
If you bring the decimal point left 6 more times it would be 79.500000
Please help! Due today. Look at the image:
Reuploaded
Answer:
3
Explanation:
2+2=4-1=3 quick maths
Carbon Monoxide is a toxic gas that is colorless and tasteless. How many moles of CO are in 1 L of the gas at STP?
28 moles
0.045 moles
22.4 moles
0.224 moles
Answer:
0.045 moles
Explanation:
Given data:
Moles of CO = ?
Volume of gas = 1 L
Temperature and pressure = standard
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
n = PV/RT
n = 1 atm× 1L / 0.0821 atm.L/mol.K × 273 K
n = 1 atm.L / 22.41 atm.L/mol
n = 0.045 mol
What type of reaction is this:
C + 02 --> CO2
Answer:
synthesis reaction
Explanation:
A + X --> AX
Answer:
Combustion reaction
Explanation:
At about what temperature does the sample change phase? Justify your
answer based on the cooling curve shown above.
A student states, “When the alcohol sample was at a temperature of 500 K, all the particles were moving faster than any of the particles were moving at
400 K" Do you agree or disagree with this student's statement? Justify your
answer.
People's actions can cause air pollution. People can plant trees to help reduce air pollution.
How does planting trees help reduce air pollution?
O A Trees take in nitrogen and dust.
B. Trees block sunlight from reaching the ground.
O c Trees produce oxygen and take in carbon dioxide.
D. Trees add nutrients to the soil that other living things need
Answer:
c
Explanation:
Describe the subatomic particles found in an atom, and
describe each one. Also, describe how they relate to each
other.
pls helpp <3
Why do molecules change the speed? (SELECT ONE)
Claim 1: Molecules speed up when energy is created and slow down when energy is destroyed.
Claim 2: Molecules speed up when they get energy from other molecules and slow down when they give energy to other molecules.
Answer:
Molecules speed up when they get energy from other molecules and slow down when they give energy to other molecules.
Explanation:
We know from the first law of thermodynamics that energy can not be created nor destroyed.
However, according to the kinetic molecular theory, molecules collide frequently with each other. All molecules in a substance do not possess equal energy hence some molecules are more energetic than others.
When a more energetic molecule collides with a less energetic molecule, the more energetic molecule transfers energy to the less energetic molecule. The less energetic molecule speeds up while the molecule that collided with it slows down due to energy transfer from one molecule to another.
(60 points + brain list)
Which is the configuration of an atom in the ground state?
A)
2-8-2
B)
2-6-1
C)
2-7-2
D)
2-7-3
Answer:
Ground state means when n = 1
and here the electronic configuration is 2:8:2