Answer:
The atomic mass
Explanation:
Answer: atomic mass
I need to right a journal entry for school but i don't know what to put Write a journal entry from the perspective of a particle of light,
called a photon. Your story should follow the photon as it
travels from a star in the Milky Way that is 25 light years away
from Earth, all the way to the eye of a young person gazing up
at the night sky through their bedroom window. Compose your
entry in complete sentences.
it is for my 5 grad sicenc
Answer:
here you go
Explanation:
someone help me on this but i still got a hundred
An endothermic reaction occurs when water and ammonium nitrate are combined. Which of the following statements correctly
describes the energy changes in the reaction?
OA. Energy is released because the reactants have more chemical energy than the products.
OB. Energy is absorbed because the reactants have more chemical energy than the products,
OC. Energy is absorbed because the products have more chemical energy than the reactants.
OD. Energy is released because the products have more chemical energy than the reactants.
Answer:
C.Energy is absorbed because the products have more chemical energy than the reactants.
Explanation:
15 points who can solve help plsss now
Answer:
C. Al and O2
Explanation:
The reactants are the elements or compounds that is becoming the result
So Al and O2
Hope this helps!
Describe the S-wave shadow effect of earth quakes.
Answer: The shadow zone is the area of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves. The shadow zone results from S waves being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.
Explanation: 104 to 140 degrees from a given earthquake
What are the compounds that you can find in mayonnaise
HEY!
Mayonnaise is an oil in water (O/W) emulsion; ingre- dients are primarily vegetable oil, egg yolk, sodium chloride, water and vinegar. Its relative stability towards microbial spoil- age has been attributed to the high salt content (in the water phase) and low pH, due to the vinegar.
thank me later
carryonlearing
Solve the following problems and show the complete solutions.
1. How many moles of Carbon Dioxide is equivalent to 1.5X1023 atoms of CO2?
2. If you have 5grams of pure Aluminum, (Al), how many atoms does it have? (Al=27)\.
3. If 3 moles Sodium (Na) reacts with exact Chlorine gas (Cl2) in this reaction: 2Na + Cl2 ---> 2NaCl How many mole of Sodium Chloride (NaCl) will be produced?
4. Give the mass percent composition of Potassium, Sulfur and Oxygen in a molecule of Potassium Sulfate: K2SO4.(atomic mass: K=39, S=32).
5. If 162g of Aluminum reacts with 144g of Oxygen gas to form Aluminum oxide, what is the mass percentage of Aluminum?
6. A sample was analyzed and found to contain 40% Carbon. 6.71% Hydrogen and 53.29% Oxygen. If the molecular mass of this compound is 18.16g/mol, what is the empirical and molecular formula of this compound?
The molecular formula of the compound is C6H12O6.
1) We know that;
1 mole of CO2 contains 6.02 X 10^23 atoms
x moles of CO2 contains 1.5 X 10^23 atoms
x = 1 mole X 1.5 X 10^23 atoms /6.02 X 10^23 atoms
x = 0.25 moles of CO2
2) 1 mole of pure Al has 27 g
x moles of Al has 5 g
x = 1 mole × 5 g/ 27 g
x = 0.19 moles
If 1 mole of Al contains 6.02 X 10^23 atoms
0.19 moles of Al contains 0.19 moles × 6.02 X 10^23 atoms /1 mole
= 1.14 X 10^23 atoms
3) From 2Na + Cl2 ---> 2NaCl;
2 moles of Na produces 2 moles of NaCl hence 3 moles of Na will also produce 3 moles of NaCl.
4) The molar mass of K2SO4 is obtained from;
2(39) + 32 + 4(16) = 78 + 32 + 64 = 174 g/mol
Now;
Percentage by mass of K = 2(39)/ 174 × 100/1 = 44.8%
Percentage by mass of S = 32/174 × 100/1 = 18.4%
Percentage by mass of O = 4(16)/174 × 100/1 = 36.8%
5) The reaction equation is;
4Al(s) + 3O2(g) ----> 2Al2O3
Total mass present = 162g + 144g = 306 g
Mass percent of Al = 162g/ 306 g × 100/1 =52.9%
6)
C - 40/12 H - 6.71/1 O - 53.29/16
C - 3.33 H - 6.71 O - 3.33
Dividing through by the lowest ratio
C- 3.33/3.33 H - 6.71/3.33 O - 3.33/3.33
C - 1 H - 2 O - 1
The empirical formula is CH2O
Now;
[12 + 2(1) + 16] n = 180.16
30n = 180.16
n = 180.16/30
n = 6
The molecular formula is C6H12O6.
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Is a change in color when combining two substances normally a sign of a chemical change or a physical change?
Answer:
Change in colour is a chemical change.
Explanation:
Because when two substances combine chemically, they create (a) new substance(s) that have/has different molecular structures from the parent substances, thus mostly likely absorb and reflect light in different ways.
which best explains why water dissolves most salts?
Answer:
where are the answers?
Explanation:
50 POINTS PLEASE HELPP
Circle the compound that has the higher boiling point and explain why we see the
differences we do
Answer:
1. Ethane has a higher boiling point
2. Heptyne has a higher boiling point
3. Octane has a higher boiling point
Explanation:
1. Ethane has stronger intermolecular attractions (van der Waal's forces) than ethene and so has the higher boiling point.
2. The longer (and the straighter) the chain, the greater the opportunity for intermolecular interactions, and thus the greater the boiling point. You should look up these boilig points! n-Pentane has a normal boiling point of approx. 36 ∘C ; n-heptane boils at 98 ∘C .
3. Octane has a high boiling point, because its molecule contains 8 Carbon atoms, and with increasing molecular weight of hydrocarbon its boiling temperature increases.
the high electrical conductivity of metals is primarily due to
High conductivity of metals is caused by electrons that are free to move through the lattice.
hope this helps!
Select from the unit conversion factor options below to determine the mass in grams of 1.204 × 1024 atoms of carbon.
1 mol C/ 6.02 x 1023 atoms C, 6.02 x 1023 atoms C / 1 mol C
12 g C / 1 mol, 1 mol / 12 g C
a
12040 g
b
24 g
c
204 g
d
1.99 g
Answer:
option a is the answer
Explanation:
bye bye
What is a net ionic equation?
9. Any body of rock or sediment in which
water can flow and be stored is called a(n)
a. well.
b. aquifer.
c. sinkhole.
d. artesian formation.
Answer:
It's option b) Aquifer.
Do cells have atoms?
Answer:
Ye? everything is made up of atoms so sure
which option can be classified as a pure substance
A. solution
B. compound
C. homogeneous mixture
D. heterogeneous mixture
Answer:
B. compound
Explanation:
A pure substance can be an element, which consists of only one type of atom and cannot be broken down by a chemical change, or a compound, which consists of two or more types of atoms.
Which statement about the Periodic Table is correct?
A Elements are arranged in order of decreasing proton number.
B Group number is the number of electron shells in atoms of the elements in the group.
C Group numbers can be used to predict the charges of ions.
D Metallic character increases left to right across a period.
answer :c
explanation :
group numbers can be used to determine the number of electrons in the outer most shell thus if the group numbers are above four then the elemnts are negative ions if less than four then posetive
which pair of atoms constitutes a pair of isotopes of the same element?
Answer:
element with same number of protons but different number of neutrons
brainliest plzzzzz
What is an allotrope?
a) The same atom with a different number of neutrons
b) A radioactive substance
c) An alternative form of an element
d) Diamond
A container that can't expand, may explode from the ________ in pressure.
Which of the following is not an alteration of a document?
additions
obliteration
erasure
O all of these answers
charring
None of these answers
ill give brainley
Using the periodic table, choose the more reactive nonmetal.
Br or As
Br and As:
Bromine is more reactive as reactivity increases on moving from left to right in p-block
Why are earthworms called as “friends of farmers”? Answer in no less than 4 sentences
Answer:
Organic matter composted with earthworms, often known as vermicompost, has been demonstrated in studies to have disease-suppressing qualities. The earthworms loosen the soil and enrich it with humus. As a result, they are known as farmer's pals. They help the crops grow healthier and over the time have earned farmers trust.
Explanation:
Hope this helps in some way!
What is an active metal?
A. a metal that reacts with oxygen
B. a metal that is above hydrogen in the activity series
C. a transition metal
D. a metal with only one valence electron
Answer:
A metal is said to be an active metal when it reacts strongly and quickly with other elements due to the electrons in its structure and its ease of sharing the electrons with other elements. ... A metal's reactivity increases as we go from the top to the bottom of the periodic table.
Explanation:
Which of the following compounds has the general formula X3Y2?Which of the following compounds has the general formula X3Y2?
There are no above options to choose from so I am giving an example of a X3Y2 formula which is Magnesium nitride, the formula is Mg3N2.
Iron reacts with oxygen and water to create rust and hydrogen gas as shown in the chemical equation. What mass of rust, to the nearest hundredth gram, is produced in this reaction?
A) 4.3 g
B) 5.8 g
C) 16.8 g
D) 29.4 g
Answer:
i think its 5.8
Explanation:
In a bond between potassium (K) and bromine (Br),
A.
the potassium atom will gain an electron and become smaller as a cation, while the barium atom will lose an electron and become bigger as an anion.
B.
the potassium atom will lose an electron and become smaller as an anion, while the barium atom will gain an electron and become bigger as a cation.
C. the potassium atom will gain an electron and become smaller as an anion, while the barium atom will lose an electron and become bigger as a cation.
D.
the potassium atom will lose an electron and become smaller as a cation, while the barium atom will gain an electron and become bigger as an anion.
Answer:
D (But as a heads up, you wrote barium instead of Bromine)
Explanation:
The Potassium atom will lose an electron since its valence shell only has one, while Bromine has 7 electrons in its valence shell. Potassium wants to get rid of its one electron, Bromine wants to gain that one electron to get a full shell.
Potassium will become a CATION with a positive charge (since it lost an electron), Bromine will become an ANION with a negative charge (since it gained an electron)
Examine the model of the different states of matter. Select ALL of the statements that accurately describe the particles in differing states. A) Gases contain less particles. B) Gases have the greatest kinetic energy. C) Energy is removed in the change from a liquid to a gas. D) Energy is added to change from a solid to a liquid state. E) In a solid, particles are so closely packed that they can only vibrate in place.
The statements which accurately describe the particles in differing states include:
Gases have the greatest kinetic energy.Energy is added to change from a solid to a liquid state. In a solid, particles are so closely packed that they can only vibrate in place.Gases have the greatest kinetic energy which explains why its particles
move very rapidly and randomly when compared to other states of matter.
Conversion from solid to liquid or liquid to gas requires more energy being
added.
The particles in solids are tightly packed with very restricted movements
which is why they are able to vibrate at a place.
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Sasha did an experiment to study the solubility of two substances. She poured 100 mL of water at 20°C into each of two beakers labeled A and B She put 50 g of
Substance A in the beaker labeled A and 50 g of Substance B in the beaker labeled B. The solution in both beakers was stirred for 1 minute. The amount of substance
left undissolved in the beakers was weighed. The experiment was repeated for different temperatures of water and the observations were recorded as shown.
Experimental Observations
Mass of Undissolved Substance at Different Temperatures (gram)
20°C
40 °C
60°C
80 °C
Substance
А
12
11
9
8 8
B
45
40
34
31
Part 1: Which substance has a higher solubility?
Part 2: Explain your answer for Part 1
Answer:
Answer temperatures gram is correct because there is more of a mass of numbers and the numbers are higher. (don't really know this subject, just guessing, hope this helped.)
The substance A has higher solubility then substance B because the higher the temperature the easier the substance will dissolve.
What is solubility?The word solubility is defined as the ability of a substance, the solute, to form a solution with another substance, the solvent.
It can also be defined as a property that allow sugar molecule to dissolve.
It can be defined as at a given temperature, the amount of solute that can dissolve in a given amount of solvent.
In this reaction, increasing the pressure and temperature results in increased solubility. An increase in pressure causes more gas particles to enter the liquid, lowering the partial pressure.
For exothermic reaction the temperature increases with decrease in solubility and for endothermic reaction the temperature decreases with increase in solubility.
Thus, the substance A has higher solubility then substance B because the higher the temperature the easier the substance will dissolve.
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6.23 X 10^6 KL + 5.34 × 10^6 kL
Lead has an atomic number of 82. Which statement describes all neutral atoms and ions of lead?
Neutral atoms of lead must have 82 electrons. Ions must have 82 electrons, as well.
Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer.
Neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
Neutral atoms of lead must have 82 protons, but ions can have more or fewer.
The neutral atom of lead must have 82 protons while ions can have b or less than 82.
The atomic number of an element is the number of protons in the nucleus of the element.
Also, for neutral atoms, the number of protons equals the number of electrons.
In ionic form, the number of protons/electrons of an atom may vary and be different from that of the neutral form.
Positive charges mean that the ion has less proton than its neutral version while negative charges mean that it has more electrons than its neutral version.
Thus, the neutral atom of lead will contain an equal number of protons as the electrons while its ionic form can have more or less than 82 protons.
More on atoms can be found here: https://brainly.com/question/803445?referrer=searchResults