When moving down a Column in the periodic table what stays the same ?
Answer:
Explanation:
When we go down in a column , we are going down in a period . In going down , one additional orbit go on adding to the atom . But the total number of electrons in the outermost orbit which is also called valence electron remains the same .
For example , when we go down in the first group A , the outermost orbit go on changing like 1 s¹ , 2 s¹ , 3 s¹ . 4 s ¹ etc which represents hydrogen , lithium . sodium , potassium etc.
So we see that , it is number of valance electrons that remains constant.
who can answer question 7
A student wants to find out if drinking coffee will affect the amount of sleep she has everyday. She collected data of cups of coffee that she drank to how much hours of sleep she got everyday. What would you plot on the y-axis?
Hours of sleep
Independent variable
Manipulated variable
Cups of coffee drank
Answer:
hours of sleep
Explanation:
because she is trying to collect data to see how much she would sleep.keywords how much hours of sleep she got everyday answer what they are asking you the answer is simply
You plot hours of sleep on the Y-axis while the cups of coffee drink on the X-axis. Thus, the correct option for this question is A.
What is the significance of plotting graphs?The significance of plotting graphs is to represent a relationship between different sets of variables with respect to one another. The purpose of a graph is to present data that is too complicated to be described in the text.
According to the context of this question, a student wants to determine the effect of drinking coffee on the hours of sleep. So, she is required to take the hours of sleep on the Y-axis.
Therefore, you plot hours of sleep on the Y-axis while the cups of coffee drink are on the X-axis. Thus, the correct option for this question is A.
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What lead to the discontinued use of DDT? What were its effects on people? Nature? People- Nature-
Need help with this
Answer:
C option is the correct answer
If Thomson was asked about Dalton's Atomic Theory, what would he say? (2+ sentences)
"Through my own experiments, I have discovered the existence of a previously unknown subparticle-the electron. Because of this, Dalton's conclusion that atoms are indivisible particles is incorrect."
Which decimal is equivalent to 56?
Answer:
The answer is 0.56
Explanation:
your welcome.
Answer:
The answer is 0.56
Explanation:
i think so
Which of the following properties of an unknown substance would allow it to be classified as a pure substance ?
A- can be dissolved into a solution
B- has a definite composition throughout
C- combines easily with other substances
D- is made of a single element or compound
D because that’s the only one that makes sense
Pure substances typically only include one type of atom or molecule and are homogeneous in nature. The majority of these chemicals have a consistent or homogeneous makeup. Thus, option C is correct.
What is pure substance?Elements are pure compounds that cannot be chemically broken down into less complex ones. Iron, gold, sulfur, oxygen, and oxygen are some well-known elements.
Because it cannot be converted into a more basic substance, an element is an example of a pure substance. Examples of pure substances include water, neon, and sodium chloride (NaCl) (table salt).
One element or a few related compounds make up pure substances. A kind of matter with a predictable chemical composition and physical properties is referred to as a chemical substance.
Homogeneous mixes are made up of two or more components or compounds that cannot be seen separately from one another.
Therefore, a single element or compound show properties of pure substance.
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You and your friends were studying lists of spelling and vocabulary lists. It seemed like everyone could easily remember the first word on the list and the fifteenth word on the list. It seemed very hard to remember the words in the middle of the list. What is the hypothesis?
Answer:
you have a bad memory?
Explanation:
A student determines the volume of a rock is 12.3mL, but the rock is
actually 12.5mL. What is the percent error? Select the BEST answer.
Answer:
1.6%
Explanation:
12.5 ml - 100%
12.3 ml - x %
x = (12.3*100)/12.5
x = 98.4%
Error = 100 - 98.4 = 1.6%
calculate the mass of 3.011×10^24 molecules of water...................... plzz i need it asap plzz help me plzz
Answer:
90.10 g
Explanation:
Step 1: Given data
Number of molecules of water: 3.011 × 10²⁴ molecules
Step 2: Calculate the moles corresponding to 3.011 × 10²⁴ molecules of water
We will use Avogadro's number: there are 6.022 × 10²³ molecules of water in 1 mole of molecules of water.
3.011 × 10²⁴ molecules × (1 mol/6.022 × 10²³ molecules) = 5.000 mol
Step 3: Calculate the mass corresponding to 5.000 moles of water
The molar mass of water is 18.02 g/mol.
5.000 mol × 18.02 g/mol = 90.10 g
How do researchers select a sample that is representative of its population
Explanation:
Using stratified random sampling, researchers must identify characteristics, divide the population into strata, and proportionally choose individuals for the representative sample. ... For example, individuals who are too busy to participate will be under-represented in the representative sample.
What happens to the price of the mineral that was extracted when mining companies are required to reclaim the land that they used for mining? Please help me.
Does it go down
Increase
No effect
Or stays the same
Answer:
innerdisactive react to be step counter function.
Explanation:
i feel
The modern atomic theory has been updated over the years as new observations of the atom have been made. What do these changes say about the strength of the modern atomic theory
Answer:
The answer is "It updates reinforce the idea, because it has been checked and modified several times, making it longer lasting".
Explanation:
The description of its empirical data throughout the world is a scientific principle. It's also based on facts and is often extensively tested by researchers. Repetitive done by scientists testing helps to enhance its body of knowledge. As just a result of advances in technology, after observation, data collection, and findings evaluation, scientific facts are checked, modified, and verified.
How long will a 25.00 g
sample of americium-241
toke to decay to form a 6.25
g sample of americium-241?
Answer:
Hope it helps.
Explanation:
It decays by beta particle emission into xenon-131. After eight days have passed, half of the atoms of any sample of iodine-131 will have decayed, and the sample will now be 50% iodine-131 and 50% xenon-131
Heavy unstable atoms will continuously emit radiation and will undergo nuclear decay to form stable products. 25 g of americium -241 will take 39 years to decay into its 6.25 g sample.
What is radioactive decay?Heavy unstable nuclei undergo decay when they emit radiations of alpha, beta or gamma particles. After that they will form stable isotopes or other lighter nuclei after emitting these charged particles.
The time an unstable nuclei takes to decay into half of its initial amount is called half life time. The half life time of Americium -241 is 432 years. Thus half life time of 25 g of Am-241 is
= (25 × 432 )/241
= 44.81 years.
The decay constant k can be calculated as follows:
k = 0.693 /half life time
= 0.693 /44.81 yrs
= 0.015.
Now the time taken for the decay process is calculated by the following equation:
t = 1/k log (25/6.25)
= 1/0.015yr-1 log (25/6.25)
= 39 years
Hence, 5 g of americium -241 will take 39 years to decay into its 6.25 g sample.
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Stars form inside giant clouds of gas and dust. What are these giant clouds of gas and dust called?
A.) Supernova
B.) Quasar
C.) nebula
D.) Black hole
Before you start an investigation, you see the Hazard symbol for Electrical Hazard. What safety steps should you follow when conducting this investigation?
Explanation:
Safety hazards means they are are the unsafe working conditions which can cause the workmen injury, illness, or death. Safety hazards are some of the most common risks at the workplace.
Electrical hazards may be defined as a place or a condition which is dangerous and where a person working can come in contact with electrical contact with some energized equipment or any electrical conductor. There is always danger or a chance for the workmen to get injury or get a flash burn while working.
The safety steps are :
1. Follow the instruction properly
2. Take proper safety measures like wearing gloves, shoes, not touching any live wires, etc.
3. Follow the clean up procedure properly.
Answer:
The safety steps are :
1. Follow the instruction properly
2. Take proper safety measures like wearing gloves, shoes, not touching any live wires, etc.
3. Follow the clean up procedure properly.
Explanation:
The law of conservation of energy states that energy can neither be created nor destroyed; however, if you stretch out a ball in your hand and let it freely drop, the ball will not quite bounce back up to the height you dropped it from. Which of the following best explains why this happens? *
The pull of gravity negates the law of conservation of energy.
Some of the energy has to be used up to push the ball back into the air, destroying it forever.
The ball falls too quickly, so the energy does not have enough time to fully recharge.
Some of the energy is released into the air as heat (thermal energy) due to friction.
which answer is it? help
Answer: the last one:)
Explanation: energy cannot be destroyed but can be transfered
(called energy transfer).
What are two examples of a chemical change
Answer:
1.Cooking an egg
2. Burning wood
Hope it helps :)
Round off the following quantities to the number of significant figures indicated in parentheses: 69.733 g (2)
Answer:
70
Explanation:
There are 5 significant figures in the problem. Since it has a decimal point, we start on the left hand side and work our way to the right. You would end up at 69, but then you have to round up since the next number is a 7, which is greater than or equal to 5.
Part D
What does the number on the top right of the symbol show? If the value here is 0, what does that mean
Answer:
Explanation:
The number on the top right of the symbol shows ATOMIC NUMBER , if it is written alone only one digit or number overall .
And if the number is also in bottom left then bottom left number will be ATOMIC NUMBER and top right will be MASS NUMBER
Hope this will help you *-*
Answer:
Explanation:
The number at the top right shows the electrical charge of the atom. A value of 0 means the atom is neutral, which means that the atom has the same number of electrons and protons.
Which condition might develop if people eat contaminated raw or undercooked fish?
A. Cyclosporiasis
O B. Cryptosporidiosis
C. Giardiasis
O D. Anisakiasis
Physical and chemical properties
Answer:
Chemical properties
-It is not reverseable
-Change in energy is seen
-It is permanent change
-The change take place in both physical and chemical properties of matter
Physical properties
-The change takes place only in physical property of matter
-It can be reversed back
-It is temporary change
-Change in energy is not seen
Coyotes and oak trees are unicellular organisms?
Answer :
Multicellular organismsExplanation :
Coyotes are multicellular organisms.
Trees are multicellular organisms. They are made up of eukaryotic cells, which are complex cells full of organelles.
Coyotes and oak trees are not unicellular organisms but are multicellular organisms.
Unicellular organisms are living organisms that consist of only one cell. These organisms are complete and functional in their single-cell structure, carrying out all essential life processes, such as respiration, nutrition, reproduction, and growth, within that one cell. Examples of unicellular organisms include bacteria, archaea, protozoa, certain algae, and some fungi.
Coyotes and oak trees are multicellular organisms made up of many cells. Coyotes are mammals, and oak trees are plants, both of which are complex organisms with specialized tissues and organs. In contrast, unicellular organisms, such as bacteria and protists, carry out all life processes within a single cell.
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Completely classify jet fuel.
Element
Heterogeneous Mixture
Pure Substance
Compound
Homogeneous Mixture
Mixture
Answer:
Mixture
Explanation:
A mixture is defined as a material formed from the combination of two or more different substances.
Jet fuel is a mixture of hydrocarbons including crude oil petroleum and kerosene or gasoline. Jet fuels are made by the process of refining and blending of different petroleum and kerosene.
Hence, the correct option is "Mixture".
A hydrogen electron is elevated from level 1 to level 2. Another electron is elevated from level 2 to level
4. The transition requiring the greatest energy change is
Answer: level 2 to level 4
Explanation:
Answer:
Level 2 to Level 4
Explanation:
Edge 2021
What is the correct measurement for solubility?
what is The chemistry of living things and living systems created a new
combined field in science
Answer:
The answer is biochemistry
Explanation:
Biochemistry is a field of science that studies the chemistry and chemical processes involved in a living system. These chemical processes include glycolysis, gluconeogenesis, citric acid cycle, pentose phosphate pathway among others. Biochemistry studies the relatedness of these processes, the importance of these processes and how these processes can or cannot be regulated.
What are five ways to identify a chemical reaction
Answer:
A chemical reaction occurs when a substance is rearranged to form a new substance. It is possible to identify if this has taken place from one of the five signs of chemical change. These changes include color change, temperature change, precipitate formation, gas production and light emission.
Explanation:
hope it helps :))
Answer:
A chemical reaction occurs when a substance is rearranged to form a new substance. It is possible to identify if this has taken place from one of the five signs of chemical change. These changes include color change, temperature change, precipitate formation, gas production and light emission.
hope it helps :)
T or F: All electrons are alike
Answer:
True
Explanation:
Every electron in the universe has exactly the same mass, and exactly the same charge.