Answer:
A) when a catalyst is added
Explanation:
The missing options are:
A) when a catalyst is added
B) when the temperature drops
C) when the pressure is lowered
D) when the molecules are large and bulky
A catalyst increases the rate of a chemical reaction without undergoing a permanent chemical change. They provide an alternative pathway to the reaction which has a lower activation energy than the non-catalyzed mechanism, this increase the reaction rate.
what element on the periodic table has a mass number of 155 and 99 for the number of electrons
Final answer:
The element with 99 electrons is Einsteinium (Es), and a mass number of 155 refers to the total number of protons and neutrons, indicating a specific isotope of Einsteinium with 56 neutrons.
Explanation:
The question asks about an element with a mass number of 155 and 99 for the number of electrons. Firstly, the number of electrons in an atom determines which element it is, as the number of electrons equals the number of protons in a neutral atom, known as the atomic number. With 99 electrons, we are referring to the element Einsteinium (Es), which is a synthetic element located in the actinide series of the periodic table.
The mass number mentioned, 155, typically refers to a specific isotope of an element, considering the mass number is the sum of the protons and neutrons within an atom's nucleus. Since Einsteinium has 99 protons (because it has 99 electrons), an isotope with a mass number of 155 would then have 56 neutrons (155 - 99 = 56).
It's also important to note that the mass number shown in parentheses on the periodic table represents the mass number of the most stable or most commonly occurring isotope for that element.
When cellular respiration occurs, food energy is converted into chemical energy in the way of ATP, ______ and _____ are the products of this process. Spell check
A gas occupies 200 mL at -73°C. To have the same gas occupy 300 mL:Should the temperature be increased or decreased?
Answer:
decreased i think
Explanation:
What is a hypothesis?
Answer:
a possible explanation or answer to a scientific question that is based on prior knowledge or research and is testable
what do all electrolytes have in common?
Final answer:
Electrolytes share the property of being able to conduct electricity when in solution because they dissociate into ions. Ions like sodium, potassium, and chloride are vital for body functions such as nerve transmission and water balance. Nonelectrolytes, which do not dissociate into ions, cannot conduct electricity.
Explanation:
All electrolytes have the common property of being able to conduct an electric current when dissolved in water or melted. This is because electrolytes are composed of ions, which are electrically charged particles. When these ions are in solution, they move towards electrodes of opposite charge, enabling the flow of electricity. For instance, when sodium, potassium, and chloride dissolve in water, they dissociate into Na+, K+, and Cl- ions, respectively. This dissociation into ions is what makes these substances electrolytic.
Sodium, potassium, and chloride are particularly important in the human body for their roles in nerve impulse conduction, muscle contractions, and regulating water balance. They, along with other cations like calcium and magnesium and anions such as bicarbonate, phosphate, sulfate, organic acids, and proteins, help maintain the body's ionic balance, acid-base balance, and osmotic pressure in bodily fluids. Electrolytes are crucial for maintaining life processes.
By contrast, nonelectrolytes do not dissociate into ions and therefore do not conduct electricity when dissolved or melted. Substances such as glucose and ethylene glycol are examples of nonelectrolytes.
The temperature of a sample of water is changed from 10°C to 30°C. The same change in Kelvin would be A) 20 B) 100 C) 273 D) 303
The temperature of a sample of water is changed from 10°C to 30°C. The same change in Kelvin would be 20 K. Thus option A is correct.
What is temperature?Temperature is defined as a measurement of an object or substance's warmth or coldness in relation to a reference value.
Temperature can also be defined as the average kinetic energy of the particles in an object.
Temperature scale is defined as a means of indicating or measuring temperature in relation to a unit of measurement and a starting point (0 or zero).
There are basically three types of temperature scale we use.
Celsius scaleKelvin scaleFahrenheit scaleThus, the temperature of a sample of water is changed from 10°C to 30°C. The same change in Kelvin would be 20 K. Thus option A is correct.
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Is there any way to predict the exact location of any, one marble drop on the target?
No, there is no way to predict the exact location of a marble drop due to various factors that influence its motion. However, we can make mathematical predictions and calculate the range of possible locations based on initial conditions and the laws of physics.
Explanation:No, there is no way to predict the exact location of any one marble drop on the target. The reason for this is that the motion of a marble, or any object, is influenced by various factors such as air resistance, initial velocity, and the surface it is dropping on. These factors can introduce variability into the motion, making it difficult to predict the exact landing spot.
However, we can make mathematical predictions and calculate the range of possible locations for the marble to land based on the initial conditions and the laws of physics.
To better understand the motion of objects in free fall, you can perform the take-home experiment as suggested. By dropping a marble, a ball, a spoon, and a piece of paper from the same height, you can observe how the objects behave and make observations about their motion.
In complete sentences, describe the flow of energy from the sun to producer and the to a consumer
Answer:
The chlorophyll in a plants leaves absorbs light energy from the sun which is then later used to make glucose and oxygen. Consumers eat the plants to get nutrients. Consumers get their energy from the food they eat.
Explanation:
Hope this helps :)
Which of these is an indication that a chemical reaction has occurred?
A.The melting of a substance
B.The boiling of a substance
C. The formation of precipatation
D The freezing of a substance
Please & Thank you!
which is the smallest particle into which a compound can be broken down and still remain the same compound
a comet is approaching earth what happens to the earths gravitational pull as the comet gets closer to the ground
How does thermal energy from the sun cause water to evaporate
Thermal energy from the sun heats water in various forms on Earth, causing molecules with sufficient energy to transition into water vapor, a process called evaporation. This evaporation contributes to the water cycle, storing energy as latent heat and influencing weather and climate patterns.
Thermal energy from the sun is crucial to the water cycle, specifically the evaporation of water. When the sun's energy reaches the Earth, it heats bodies of water such as oceans, lakes, and streams. As water absorbs this heat, the average kinetic energy of water molecules increases and some molecules gain enough energy to overcome the attractive forces holding them in the liquid. This process causes those water molecules to escape into the air as water vapor.
Evaporation doesn't just happen over water bodies; it can also occur from land surfaces and within soil where there is moisture. The energy from the sun also contributes to the process of sublimation, where ice and snow convert directly into water vapor without becoming liquid first. Plants play a part through transpiration, which is the release of water vapor into the atmosphere from plant leaves.
An important concept to understand is that during evaporation, the energy of the sun is stored as latent heat in the water vapor. This latent heat is released when water vapor condenses to form clouds, which then can lead to precipitation, completing a part of the water cycle. The continuous exchange of heat energy, facilitated by the sun, is fundamental in driving weather and climate patterns across the globe.
The first picture is for the first question and the second picture is for the 2nd question
Which is the topmost layer of the rock?
Layer A
Layer B
Layer C
Layer D
Which statement about the rock fossils is true?
Organism X existed for a short period of time.
Organism Y became extinct before organism X.
Organism X and organism Y existed at the same time.
Organism Z became extinct much before organism X.
Scientists find an artifact next to an index fossil. What can they conclude about the unknown age of the artifact?
The artifact is older than the index fossil.
The artifact is younger than the index fossil.
The artifact is approximately the same age as the index fossil.
The artifact's age is not related to that of the index fossil.
What process uses analysis of the decay of atomic particles to determine exact age?
Radioactive dating
Law of superposition
Relative dating
Geologic time
Answer:
1. B
3. C
4. its radioactive dating i learned about this
You serve a volley ball with a mass of 2.1 kg. The ball leaves your hand with the speed of 30 m/s. The ball has __________ energy. calculate it
What are two physical properties that can help you identify a substance?
Final answer:
Two physical properties that are useful for identifying a substance are its density and melting point. Density helps determine whether the substance will float or sink, while the melting point assists in distinguishing substances under controlled temperature conditions.
Explanation:
Two physical properties that can help you identify a substance are its density and melting point. Density is a measure of how much mass is contained in a given volume and can be particularly useful when determining whether a substance will float or sink when placed in a fluid.
The melting point—the temperature at which a substance changes from a solid to a liquid—can also be unique to a substance and is especially useful when comparing similar looking materials under controlled temperature conditions.
For example, pure water has a density of 1 gram per cubic centimeter at room temperature, and ice, which is solid water, will float in liquid water due to its lower density. The melting point of water is 0 degrees Celsius, which is a well-known physical constant.
On the other hand, substances like gold and silver have melting points of 1064 degrees Celsius and 961.8 degrees Celsius, respectively, and much higher densities, allowing for easy distinction from substances with similar appearance but different physical properties.
Why do giraffes have long necks that allow them to eat leaves in trees? A. for acquiring energy
B. for reproducing
C. for maintaining structure
D. for protection
how should the student label each circle in the diagram
Answer:
Reaction A is chemical, Reaction B is nuclear
Explanation:
Cells that perform a specific function in an organism ______.
Perform all of the functions
Are specialized
Are all the same
Can survive on their own
PLEASE NO INCORRECT ANSWES AND PLEASE ANSWER QUICKLY
What is asubstance that flows Called
ANSWER ASAP! PLEASE DOUBLE CHECK!
How do instantaneous speed and average speed differ?
Instantaneous speed happens all the time, but average speed only happens once per hour.
Instantaneous speed is always faster than average speed.
Instantaneous speed is the speed of an object at a specific time, but average speed is the total distance over the total time.
Instantaneous speed is always slower than average speed.
Answer:
Explanation is given below.
Explanation:
It is very easy to understand the difference between average speed and instantaneous speed.
The explanation given by you are rewritten in the correct way.
The instantaneous speed is the speed of an object at a particular instance of time while its moving or covered some distance or just started moving. For example finding the speed of your car at 20th minute after you depart from your home no matter you have to travel more to reach the destination. Its not correct to say that average speed happens per hour but, the average speed is the total distance covered by an object per unit total time taken by the object to cover that distance.Its not necessary that instantaneous speed will always be more than the average speed. It can differ.The statement is right that: Instantaneous speed is the speed of an object at a specific time, but average speed is the total distance over the total time. As it is described above. Its not necessary that instantaneous speed will always faster or slower than average speed as described in point number 2, but while finding the AVERAGE speed the total time will always more than instantaneous time.Answer:
Lets cut to the chase.
Explanation:
Its C. i took the test
what is the total number of atoms in the formula below? NH3
In the periodic table, which elements had complete outer shells? Also include name and symbol
Do water molecules leave or enter a cell in an isotonic solution?
what does an atomic number represent in an atom?
Answer:
The atomic number is the number of protons in the nucleus of an atom.
Explanation:
Atoms have 3 main subparticles: protons, neutrons and electrons. Protons have positive charge, neutrons don't have any charge, and electrons have negative charge. Both protons and neutrons are located in the nucleus while electrons move around the nucleus.
Elements that have the lowest density of all the metals are called
1.Why is there more mass in a metal spoon compared to a plastic spoon?
Metals have higher density than plastics. Hence they weigh more on small volume. Therefore a metal spoon has higher mass than a plastic spoon.
What is density ?Density of an object is the measure of the mass per unit volume of the substance. It describes how closely its particles are packed in its volume. The density of a substance depends on the bond type, pressure and temperature as well.
Metals are electropositive elements with greater densities. The metallic particles are held together by strong metal - metal bonds. This makes the metal lattice denser and hard.
Therefore, a metal spoon will have greater density and thereby mass in a given volume than plastic spoon which is of very less density compared to the metals.
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What does erosion do?
A. breaks rocks apart
B. cements sediments
C. moves bits of rock and soil
D. forms rocks
Answer:
C. Moves bits of rocks and soil
Explanation:
as learnt in elementary, weathering is the geological process of breaking rocks and sediments apart. Which means the answer is not A.
Also the sediments is part of the rock cycle so we can eleminate B
And erosion is the geoloical term of moving rocks and sediments into other places depending on the type of erosion. Which proves the answer might be C, But lets chech D first.
Phyical changes forms rocks, so the answer is not D
Which narrows back down to C, which is how we got our answer.
Hope it helps
If a mineral has a metallic shine to it, which property of a mineral is being measured
The property of the mineral is luster.
A metallic luster would reflect light the same way as a metal would.
D- Luster is your answer
A reaction produces 0.829 moles of H2O. How many molecules are produced?
The reaction produces approximately 4.987 x 10^23 molecules of H2O.
Explanation:To determine the number of molecules produced, we need to convert the given moles of H2O to molecules. One mole of any substance contains Avogadro's number of molecules, which is approximately 6.02 x 10^23 molecules. Therefore, to convert moles to molecules, we multiply the number of moles by Avogadro's number.
0.829 moles x (6.02 x 10^23 molecules/mole) = 4.987 x 10^23 molecules
This representation shows the two hydrogen atoms (H) bonded to the oxygen atom (O). The angle between the hydrogen-oxygen-hydrogen atoms is approximately 104.5 degrees. Water is a polar molecule, meaning it has a slight electrical dipole moment due to the unequal sharing of electrons between the oxygen and hydrogen atoms, resulting in a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms. This polarity gives water unique properties, such as its ability to form hydrogen bonds and its importance in various biological and chemical processes.
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some foods like enduves or brussel sprouts have a bitter taste recipe books often recommend cooking them with tomatoes vinegar or lemon juice why?
Recipe books suggest adding acidic ingredients like tomatoes, vinegar, or lemon juice to bitter foods to make them more palatable. The acidity helps to neutralize bitter flavors and enhances the dish's overall taste by adding a more acceptable sour taste.
The perception of bitterness in foods such as endives and Brussels sprouts is linked to the presence of certain compounds that can be indicative of toxic substances. The taste buds on the posterior tongue are especially sensitive to bitter tastes as a protective mechanism to induce the gag reflex to prevent the ingestion of potentially poisonous substances. To counteract the bitterness and make these foods more palatable, recipe books often recommend adding acidic ingredients like tomatoes, vinegar, or lemon juice. These acids can neutralize the bitterness to some extent and enhance the overall flavor profile of the dish by adding a sour element that is generally more acceptable to our taste palette.
Acids like citric acid found in lemon juice and acetic acid in vinegar are known to sour tastes which can help to balance or mask the bitter flavor. Moreover, acidic ingredients might also interact with volatile compounds that contribute to the bitterness, neutralizing them and making the food more enjoyable to eat.