Answer:
Explanation:
Chemical equation
the atomic number is the number of protons, but in a neutral atom it is also the number of _____. A. none of these B. electrons C. neutrons D. nuclei
Answer:
Electrons
hope it helps
Most of the matter making up the earth is composed of
A. gases
B. compounds
C. mixtures
Most of the matter making up earth is composed of compounds. I think
2. Energy that is stored in an object because of its temperature is called ___________________. *
Answer:
Thermal Energy
Explanation:
The thermal energy of an object increases as the temperature increases, causing atoms and molecules to move faster. When the temperature decreases, the thermal energy decreases, causing atoms and molecules to move slower. Another term for thermal energy is heat energy.
How many mililiters are there in a .5 M solution in which 60 grams of Li?
Answer:
10
Explanation:
Calculate the volume of carbon dioxide given off at r.t.p. when 0.9g of glucose ferments.
C6H12O6 (aq) = 2C2H5OH (aq) + 2CO2 (g)
Answer:
2H+(aq) + CaCO3(s) → Ca2+(aq) + H2O(l) +. CO2(g). [ 2]. Award [1] for correct reactants and products. Award [1] if the ... Exercises. 1 Reaction gives off a gas: change in volume could be measured.
The heart works directly with which
Liver
Lungs
Kidneys
Brain
Answer:
Lungs.
Explanation:
They bring the blood throughout the body, to help it function properly
Science please help. I will add you and please don’t give me any random websites
Answer:
C
Explanation:
Answer:
D)
Explanation:
On land, volcanoes form when one tectonic plate moves under another. Usually a thin, heavy oceanic plate subducts, or moves under, a thicker continental plate. When this happens, the ocean plate sinks into the mantle.
In an exothermic the change in enthalpy is usually
Positive, because the potential energy of the reactants is higher than the potential energy of the products
Neutral, because the potential energy of the products and reactants cancel each other out.
Negative, because the potential energy of the reactants is higher than the potential energy of the products
Positive, because the potential energy of the reactants is lower than the potential energy of the products
Answer:
Negative, because the potential energy of the reactants is higher than the potential energy of the products
Explanation:
Exothermic reaction is a reaction in which heat is released to surrounding. This is due to the fact that the heat content of the reactant is higher than the heat content of product thus producing a negative enthalpy change (ΔH) i.e
Enthalpy change = Heat of product – Heat of reactant
ΔH = Hp – Hr = negative
Considering the options given in the question above, the correct answer is:
Negative, because the potential energy of the reactants is higher than the potential energy of the products
What is the percent by mass concentration of 1000 ml of a solution (d=1.5 g/ml) that contains 50 g of solute in it?
Answer: The percent by mass concentration is 33.3 %
Explanation:
Mass percent is the ratio of mass of solute to the mass of solution in terms of percentage.
mass of solute = 50 g
mass of solution = [tex]{\text {density of solution}}\times {\text {volume of solution}}=1.5g/ml\times 1000ml=1500g[/tex]
Mass percentage = [tex]\frac{50g}{1500g}\times 100\%=33.3\%[/tex]
Thus percent by mass concentration of 1000 ml of a solution (d=1.5 g/ml) that contains 50 g of solute in it is 33.3 %
2. The diagram shows a Zn/MnO2-KOH alkaline dry cell.
In your response, do the following:
• Label all parts.
• Label the cathode and the anode, including the charges on each.
• Show the flow of electrons.
• Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.
Answer:
1. Graphite rod (cathode)
2. Positive terminal
3. Solid zinc layer (anode)
4. Paste (reduction takes place here)
5. Negative terminal
Explanation:
This was the only thing i could find on it. hope this helps.
Answer:
Explanation:
• Label all parts.
1. Cathode or Graphite Rod
2. Positive terminal
3. Anode or Solid Zinc layer
4. Electrolyte Paste (reduction takes place here)
5. Negative Terminal (maybe this could also be the Zinc casing)
• Label the cathode and the anode, including the charges on each.
The anode is the zinc layer is negatively charged and the cathode is the graphite rod is positively charged.
• Show the flow of electrons.
The zinc casing is oxidized and the electrons flow along the zinc layer, into the negative terminal, and then out the negative terminal. The electrons move from the wire to the graphite rod. Then from the rod the electrons move to the paste, then the past goes through reduction. The anode gets a negative charge as electrons are released, and the cathode gets a positive charge as the electrons, which are negatively charged, are consumed.
• Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.
Alkaline dry cells use spontaneous oxidation-reduction reactions to convert chemical energy to electrical energy. According to the lesson ‘’Half-reactions are combined in a small casing, but still separated into half-cells.’’
How many moles does 21.7 L of gas at STP represent?
Answer:
The number of moles represented by 21.7 L is 0.96875 moles
Explanation:
The volume occupied by one mole of a gas which consists of (approximately) 6.022 × 10²³ elementary at STP is 22.4 L. The volume is known as the molar volume of gas
Therefore, the number of moles, 'n', present in 21.7 L of gas at STP is given as follows;
The number of moles represented by 22.4 L = 1 mole
∴ The number of moles represented by 21.7 L = 1 mole/22.4 L × 21.7 L = 0.96875 moles
The number of moles represented by 21.7 L = 0.96875 moles.
Combustion engines became common in the mid-1800s when people began to use them to power ships, trains, and
machinery in factories. Combustion engines add carbon dioxide to the air, and as a result, carbon dioxide in the
atmosphere increased quickly. How did this change the total amount of energy in the Earth system, and how did this
change happen? How did this affect global average temperature?
I need help please and don’t send the fake link): < just to get points
Answer:
The correct answer is - increased the global average temperature.
Explanation:
Combustion is the process that increases the carbon dioxide in the atmosphere, which results in entering more energy into the Earth system than existed from it. Therefore, the amount of energy increased in the system of the earth or surface of the earth.
The reason behind it is that carbon dioxide trapped and redirects energy back toward the Earth's surface, which is absorbed by Earth's surface and surface increased, and global average temperature increased.
Combustion process increases the global average temperature of the earth by absorbing and emitting the energy revert back to earth.
What is combustion?Combustion is a process exothermic process in which organic molecules burns in the presence of oxygen to produce energy in the form of heat and light and CO₂ gas.
CO₂ gas is a green house gas which traps the energy of the atmosphere and revert back it into the earth surface, due to which temperature of the earth surface and atmosphere increases which results in the elevation of global average temperature.
Hence, combustion increases the global average temperature.
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Which substance is the BEST example of a compound?
Orange Juice
Salt Water
Hydrogen
Water
Answer:
I think hydrogen because Hydrogen combined with one atom with oxygen and in hydrogen peroxide. It has two atoms of hydrogen and 2 atoms of oxygen. Therfore it should be a compound.
what is the difference between isotopes and allotrope not more than three line
Answer:
An allotrope is one way that atoms can be arranged in a solid. An isotope is one way that protons and neutrons can form the same atomic element.
Evidence of a chemical change would be
A) melting
B) spinning top
C) spilled bucket of water
D)rusting car fender
Select the correct answer.
What does an atom gain or lose in an oxidation-reduction reaction?
A.
protons
B.
oxygen
C.
neutrons
D.
electrons
Answer:
D The atom gains an electron in an oxidation-reduction reaction.
Mr. Whiteman has two stock solutions of sulfuric acid (H2SO4) in the supply closet: 12.1 M and 6.0 M. If he wants to make 10.0 mL of a 1.0 M solution, which stock solution makes more sense to use? Justify with two calculations.
Answer:
12.1-M requires less volume of stock solution.
Explanation:
Hello there!
In this case, according to the foundations of dilution processes, it turns out convenient to remember that the moles of the solute before and after the dilution remains the same; for that reason we use the following equation:
[tex]M_1V_1=M_2V_2[/tex]
Relating the initial and final molarities and volumes. Now, it is seen that V2 is 10.0 mL and M2 is 1.0 M, which means that if we solve for V1 for 12.1 M and 6.0 M, we obtain the following volumes:
[tex]V_1=\frac{M_2V_2}{M_1} \\\\V_1^{12.1M}=\frac{1.0M*10.0 mL}{12.1M}=0.826mL\\\\V_1^{6.0M}=\frac{1.0M*10.0 mL}{6.0M}=1.67mL[/tex]
Therefore, since the 12.1-M solution requires less volume of stock solution, it makes sense to use this one as the initial solution.
Best regards!
Which reaction occurs when equivalent quantities of H" (or H30) and OH" are mixed?
1.
oxidation
2.
reduction
3
hydrolysis
4.
neutralization
Answer: A reaction which occurs when equivalent quantities of H" (or [tex]H_{3}O^{+}[/tex]) and OH" are mixed is a neutralization reaction.
Explanation:
When acid and base chemically combine together to form sat and water then it is know as neutralization reaction.
An acidic substance gives hydrogen ions [tex](H^{+})[/tex] on dissociation and a basic substance gives hydroxide ions [tex](OH^{-})[/tex] on dissociation.
For example, [tex]H^{+} + OH^{-} \rightarrow H_{2}O[/tex] is a neutralization reaction where an acid and base are mixed together to form water.
No salt is formed as because here the reactants are not present as compounds.
In a hydrolysis reaction, water molecule(s) is added to the reactant molecules.
For example, [tex]CH_{3}COOCH_{3} + H_2O \rightarrow CH_{3}COOH + CH_{3}OH[/tex]
Oxidation is the process of addition of oxygen to a molecule and removal of hydrogen.
Reduction is the process of addition of hydrogen in a compound and the removal of oxygen atom.
Therefore, we can conclude that reaction which occurs when equivalent quantities of H" (or [tex]H_{3}O^{+}[/tex]) and OH" are mixed is a neutralization reaction.
What is the main way energy from the Sun moves around Earth?
O
O A.
From the atmosphere
O
B.
From human energy
O
C.
From the ocean currents
Answer:
All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.
Chemistry help! Please zoom in to see better
Answer:
82.04g
Explanation:
To solve this problem, you need to find the molar mass of HCl, which is the sum of the molar mass of H plus the molar mass of Cl. The molar mass of H is 1.008g/mol while the molar mass of Cl is 35.45g/mol. Thusly the molar mass of HCl is 36.458g/mol. You have 2.25 moles of HCl, so multiply the number of moles by the molar mass to get the mass in g. In this case it is 2.25mol * 36.458g/mol = 82.04g.
If I helped, a brainliest would be greatly appreciated!
please let me know if the answer is true or false. if false, please tell me what's false about it. the word that they are wondering if it needs to be changed is highlighted
Answer:
false the answer is woody
Explanation:
those are the two types of stems
what are the chemical symbols of the particles found in the calcium chloride crystal (lattice)
Answer:
Formula and structure: The chemical formula of calcium chloride is CaCl2, and its molar mass is 110.983 g/mol. It is an ionic compound consisting of the calcium cation (Ca2+) and two chlorine anions (Cl-). The bivalent calcium metal forms an ionic bond with two chlorine atoms, as shown below.
Based on the ionic nature of calcium chloride, the chemical symbols of the particles found in the calcium chloride crystal is Ca²⁺ and Cl⁻.
What are ionic compounds?
Ionic compounds are compounds which are composed of ions.
Calcium chloride is an ionic compound composed of the ions, calcium ions and chloride ions.
The chemical formula of calcium chloride is CaCl2, and its molar mass is 110.983 g/mol.
The symbol for calcium ion is Ca²⁺
The symbol for chloride ion is Cl⁻.
Therefore, the chemical symbols of the particles found in the calcium chloride crystal is Ca²⁺ and Cl⁻.
Learn more about ionic compounds at: https://brainly.com/question/11638999
Nitrous acid is classified as an Arrhenius acid because HNO2 contains
1. OH-ions
2. 02-ions
3. NO2-ions
4. H+ ions
4) H+ions is your answer , good morning , have a great day ahead.
DUE TONIGHT!
I need help doing this question and please type an ACTUAL answer. I don’t want none of that “aNsWeR iN FiLe”. Thank you!
Calculate the specific heat (Cp) for indium metal given a 1.0 mole absorbs 53.0 J
while increasing in temperature from 297.5K to 299.5K.
Answer:
27J/Kmol
Explanation:
Heat = number of moles times the Moeller heat capacity chimes the change in temperature.
^ Q = nC△T
^ C = Q/ n△T = +53J / (1mol) (299.5K - 297.5K)
^ = 26.5 (rounded to 27)
2. How many moles of hydrogen are produced from the reaction of 3.86 moles of zinc with an excess of
hydrochloric acid?
Answer:
as per given balanced equation one mole Zn produces 1mole Hydrogen
when reacted with excess acid.
So 3 moles Zn will give 3moles Hydrogen
Explanation:
According to the balanced chemical equation, one mole of Zn produces one mole of hydrogen . Therefore, 3.86 moles of Zn metal will produce 3.86 moles of hydrogen gas.
What is mole ratio ?Mole ratio refers to the ratio of the number of moles of one substance in a chemical reaction to the number of moles of another substance in the same reaction.
It is derived from the balanced chemical equation for the reaction, which indicates the relative amounts of each substance involved in the reaction.
Mole ratio is important in stoichiometry, which is the study of the quantitative relationships between reactants and products in a chemical reaction.
The given chemical reaction is written as follows:
Zn + 2 HCl ⇒ ZnCl₂ + H₂
According to the balanced chemical equation, one mole of Zn produces one mole of hydrogen . Therefore, 3.86 moles of Zn metal will produce 3.86 moles of hydrogen gas.
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A 25°C sample of gas has a volume of 5.0 L. What will it’s volume be if it is heated to 50.0°C?
Just awnser #9#10#11#12 please ❤️ i will mark brainliest and also you get 15 points!
Answer: 9. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
10. The reasons for the differences in the surface temperature of terrestrial planets are due to their distance from the sun and the composition of their atmosphere.
11. 93.48 million miles
12. Iron core
Explanation: Hope this helped!! :)
How to know the state of elements in a reaction
Answer:
each compound or molecule is indicated in subscript next to the compound by an abbreviation in parentheses. For example, a compound in the gas state would be indicated by (g), solid (s), liquid (l), and aqueous (aq).
Explanation:
Why do people who exercise more produce more carbon dioxide ?
Answer:
When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide.
Explanation:
Because your muscles are working harder when you exercise, your body requires more oxygen and produces more carbon dioxide.
What is exercise?Exercise is characterized as a physiological movement that maintains or enhances total physical wellness. People who exercise are less likely to get diseases and to maintain a healthy weight. Type 2 diabetes, heart disease, high blood pressure, and weight gain can all be warded off with regular exercise. Leaping, jogging, or lifting weights are examples of exercises that can support bone health.
The lungs both provide the body with oxygen, which gives you energy, and remove carbon dioxide from the system, which is a byproduct of energy production. The heart pumps oxygen-rich blood to the working muscles. Because your muscles are working harder when you exercise, your body requires more oxygen and produces more carbon dioxide.
Thus, because your muscles are working harder when you exercise, your body requires more oxygen and produces more carbon dioxide.
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Which of the following groups of chemical elements would you expect to
be most alike in their physical and chemical properties?
A. Chromium, rhodium, zinc, silicon
B. Magnesium, strontium, radium, barium
C. Lithium, beryllium, boron, oxygen
D. Sulfur, selenium, chlorine, krypton
Answer: B. Magnesium, strontium, radium, barium
Explanation:
Elements are distributed in groups and periods in a periodic table.
Elements that belong to same groups will show similar chemical properties because they have same number of valence electrons.
Magnesium (Mg) , Strontium (Sr) , Radium (Ra) and Barium (Ba) are elements which belong to Group 2. They have 12, 38, 88 and 56 electrons respectively and contain 2 valence electrons each and need one electron to complete their octet.
The chemical reactivity of elements is governed by the valence electrons present in the element and thus they are alike in physical and chemical properties.