Which pattern on the periodic table is correctly predicted below?
Groups determine the number of valance electrons and periods determine the number of energy levels
Groups determine the number of energy levels and periods determine the number of valence electrons
Groups determine the number of protons, and periods determine energy levels
Groups determine the number of neutrons, and periods determine valence
Plzz
1)
At 150 C, what state of matter would water be at?
2)
Which of these three options will turn to a gas at the COLDEST temperature:
Carbon Dioxide, Gold, or Ethanol?
1. gaseous
2. Carbon Dioxide
What characteristic of life is demonstrated by maintaining a stable pH?
Answer:
Living Things Maintain Stable Internal Conditions When any living organism gets thrown off balance, its body or cells help it return to normal. In other words, living organisms have the ability to keep a stable internal environment. Maintaining a balance inside the body or cells of organisms is known as homeostasis.
Explanation:
Which method of heat transfer allows you to fry an egg in a frying pan on the stove?
Answer:
Conduction
Explanation:
Answer:
Conduction is correct
Explanation:
The amount of force needed to keep a 10 kg box moving at a constant
speed of 0.4 m/s on frictionless ice is *
ON,
0.04N
40 N
1.4 N
Answer:
ON
Explanation:
Frictional force is a force that opposes the motion of body. It is because of friction that motion can be controlled and even walking is made possible.
Now, on a frictionless surface, there is no opposition to motion. Therefore, to keep the body moving there is no force required.
If surface lacks friction, motion will continue perpetually without any hinderance.A rock rolls down a hill. Which form of energy is this an example of?
Chemical
Electrical
Mechanical
Thermal
Answer:
Mechanical
Explanation:
chemical
Explanation:
I took test 2020
Which material is found in asteroids?
Answer:
Asteroids are made of rock, metals, and other elements. Some even contain water. Asteroids that are mostly stone sometimes are more likely to lose piles of rubble. Asteroids that are mostly iron are more rock-solid.
Explanation:
Answer:
asteriods are made of rocks. asteroids that are mostly iron are more, well, rock-solid
Explanation:
g Lactate dehydrogenase is a tetrameric enzyme (144kDa) that catalyzes conversion of pyruvate into lactate to regenerate NAD in oxygen depleted muscles. a) Why in anaerobic conditions, is NADH oxidized by lactate dehydrogenase
Answer:
Kindly check the explanation.
Explanation:
NADH is oxidized anaerobic conditions by lactate dehydrogenase because in order to transform or change Pyruvate into Lactate it has to happen in an anaerobic condition that is where we hardly find oxygen(in the presence of no oxygen).
The chemical compound or say the enzyme known as lactate dehydrogenase gets its proton from NADH( in a REDOX type reaction). After getting the proton from NADH, it uses that to convert Pyruvate into Lactate.
NB: the conversion can also be done in aerobic condition but more ATP will be produced. With anaerobic condition, less ATO is produced and there is re-oxidation.
predict how many moles of nh3 would be made if 6.00 moles of h2 were used N2
Answer:
4 moles
Explanation:
The equation is 3H2 + N2 → 2NH3
so the ratio of moles would be
2:3 or 2/3
so 6*2/3 which is 4
hope this helped.
Answer:
4moles
Explanation:
Given parameters:
Number of moles of H₂ used = 6moles
Equation of the reaction:
N₂ + 3H₂ → 2NH₃
3 mole of H₂ was used to produce 2 mole of NH₃;
6 mole of H₂ will produce [tex]\frac{6x2}{3}[/tex] = 4 moles of NH₃
The number of moles of NH₃ produced is 4moles
Which of the following will increase the volume of a gas
Answer:
The volume of a gas is directly proportional to its temperature. Avagadro's Law- Gives the relationship between volume and amount of gas in moles when pressure and temperature are held constant. If the amount of gas in a container is increased, the volume increases.
Answer:
Decreasing the pressure applied to the gas.
Explanation:
Ap3x
A neutral atom becomes a positive ion when it
Answer:
Neutral atoms can be turned into positively charged ions by removing one or more electrons.
Explanation:
If there is an atom that has 9 protons and 9 electrons, removing an electron from the atom will gain a postive charge.
Why do gases diffuse more quickly than liquids?
Choose the correct answer.
A) Liquids can be compressed easily.
B)The particles in gases are not mobile.
C)Liquids are always at lower temperatures than gases.
D)Gas particles move rapidly and have space between them.
Answer:
D)Gas particles move rapidly and have space between them.
Explanation:
Matter exists in three states namely: solids, liquids and gases. The particles contained in these three states are different from one another. In the gaseous state, the particles are FAR APART from one another i.e. space exists and they move at a very fast rate in contrast to the particles of a liquid, which have less space and move slower.
This rapid movement of gas particles within a less restricted space accounts for the reason why gaseous substances DIFFUSE more quickly than liquids.
Short Answer Questions 18 points
1) What year was Mendeleev born? _______________________________________
2) Where was Mendeleev born? ______________________________________
3) Explain how Mendeleev arranged his periodic table.______________________________________
4) What were the 3 Elements that were missing from Mendeleev’s Periodic Table?
__________________________________________________________________
5) When did Mendeleev die? Exact date ____________________________________
6)Which particles are in the nucleus of an atom? ______________________________
1) He was born on February 8, 1834
2) He was born in Tobolsk, Russia
3) Mendeleev arranged the elements in order of increasing relative atomic mass.
4) Gallium, germanium, and scandium
5) He died on February 2, 1907
6) Protons (positive charge) and neutrons (neutral charge)
What is the relationship between temperature and pressure
A binary molecule consists of how many atoms?
O1
02
3
4
Answer:
2
Explanation:
BIonary bi means 2
i hope this helps :)
Matter is anything that has mass and takes up space (volume). How does volume change as matter changes state?
A. The density of matter remains the same, only energy of the atoms changes.
B. matter becomes more dense as it moves from solid to gas
C. Matter becomes less dense as it moves from gas to solid state
D. Matter becomes more dense as it moves from gas to solid state
Answer: D) Matter becomes more dense as it moves from gas to solid state
A gas expands to fill up the container of whatever shape or size. As it cools to a solid, the molecules get closer together and don't move as much (the molecules still will vibrate and move somewhat even in solid form). So effectively the volume of the object shrinks while the amount of mass stays the same. This is why the density increases when going from gas to solid.
a goup of cells that work together to perform a specific function.
Answer:
Cell Differentiation and Tissue.
Explanation:
tissues are organized communities of cells that work together to carry out a specific function.
which type of rection has the general formuial ab+cd
1 point
Which element requires the least amount of energy to remove its valence electron(s)?
barium
chlorine
oxygen
carbon
every spring has an equilibrium position which statement describe a spring at it equilibruim position?
Unless otherwise instructed, you may use the periodic table in the Chemistry: Problems and Solutions book for this question.
Which explanation accounts for why carbon monoxide is not a polar molecule?
The electronegativity differences between carbon and oxygen are not very large.
Carbon and oxygen do not form ions.
Carbon is a metal, and oxygen is a nonmetal.
There are no hydrogen atoms in the molecule.
Answer:
The electronegativity differences between carbon and oxygen are not very large.
Explanation:
Between the atoms of carbon monoxide exists a covalent bond which attaches the carbon to the oxygen.
In this type of bonding, both atoms shares a given number of valence electrons to attain chemical stability.
A substance is polar when there is a distinct charge separation between the species.
For covalent bonds, the electronegativity difference plays in important role in determining the polarity of the compound. When the difference is large, the compound will be polar but when the difference is very small or zero, no polarity will exist.
In between carbon and oxygen of carbon monoxide, the electronegativity difference is very low.
Gustavo and Beatriz are pushing on a door in opposite
directions. If the door does not move, the forces are
The net force in this scenario would be Answer: balanced and zero
Answer:
Correct
Explanation:
Balanced forces are always zero!
Answer:
Balanced
Zero
Explanation:
The density of ethanol, C 2H 5OH, is 0.789 g/mL. How many milliliters of ethanol are needed to produce 25.0 g of CO 2 according to the following chemical equation?
C 2H 5OH( l) + 3 O 2( g) → 2 CO 2( g) + 3 H 2O( l)
Answer:
11.1mL
Explanation:
The reaction expression is given as:
C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O
Given parameters:
density of ethanol = 0.789g/mL
mass of CO₂ = 25g
Unknown:
Volume of ethanol = ?
Solution:
First find the number of moles of the CO₂ from the given mass;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Number of moles = [tex]\frac{25}{44}[/tex] = 0.57mol
Then;
Find the number of moles of ethanol used;
3 moles of CO₂ is produced from 1 mole of ethanol;
0.57mole of CO₂ will be produced from [tex]\frac{0.57}{3}[/tex] = 0.19mole of ethanol
Now;
Find the mass of the ethanol from the given mole;
Mass of ethanol = number of moles x molar mass
Molar mass of ethanol = 2(12) + 5(1) + 16 + 1 = 46g/mol
Mass of ethanol = 0.19 x 46 = 8.74g
Then;
Density is the mass per unit volume of a substance;
Density = [tex]\frac{mass}{volume}[/tex]
Volume = [tex]\frac{mass}{density}[/tex]
Volume = [tex]\frac{8.74}{0.789}[/tex] = 11.1mL
Polonium crystallizes in a simple cubic unit cell with an edge length of 3.36 Å.
a. What is the mass of the unit cell?
b. What is the volume of the unit cell?
c. What is the density of polonium?
a. The unit cell is the smallest group of atom which have overall symmetry of a crystal, and from which is the entire letters can be buled built up by repetition in 3 dimensions.
b. The volume(v) of the unit cell is equal to the cell edge length (a)cubed.
c. density of polonium is 9.32g/cm3.
PLEASE HELP!! (I will mark brainiest) (REAL ANSWERS ONLY PLEASE!)
In one paragraph, using your own words, describe the structure of DNA using the following terms: phosphate, sugar, pyrimidines, purines, and bonding.
The phosphate group of one nucleotide bonds covalently with the sugar molecule of the next nucleotide, and so on, forming a long polymer of nucleotide monomers. The sugar–phosphate groups line up in a “backbone” for each single strand of DNA, and the nucleotide bases stick out from this backbone. The carbon atoms of the five-carbon sugar are numbered clockwise from the oxygen as 1′, 2′, 3′, 4′, and 5′ (1′ is read as “one prime”). The phosphate group is attached to the 5′ carbon of one nucleotide and the 3′ carbon of the next nucleotide. In its natural state, each DNA molecule is actually composed of two single strands held together along their length with hydrogen bonds between the bases.
Answer:
Explanation:
The discovery that DNA is the prime genetic molecule, carrying all the hereditary information within chromosomes, immediately focused attention on its structure. It was hoped that knowledge
of the structure would reveal how DNA carries the genetic messages that are replicated when chromosomes divide to produce two identical copies of themselves. During the late 1940s and early 1950s, several research groups in the United States and in Europe engaged in serious efforts—both cooperative and rival—to understand how the atoms of DNA are linked together by covalent bonds and how the resulting molecules are arranged in three-dimensional space. Not surprisingly, there initially were fears that DNA might have very complicated and perhaps bizarre structures that differed radically from one gene to another. Great relief, if not general elation, was thus expressed when the fundamental DNA structure was found to be the double helix. It told us that all genes have roughly the same three-dimensional form and that the differences between two genes reside in the order and number of their four nucleotide building blocks along the complementary strands.
Now, some 50 years after the discovery of the double helix, this simple description of the genetic material remains true and has not had to be ap- preciably altered to accommodate new findings. Nevertheless, we have come to realize that the structure of DNA is not quite as uniform as was first thought. For example, the chromosome of some small viruses have single-stranded, not double-stranded, molecules. Moreover, the precise orientation of the base pairs varies slightly from base pair to base pair in a manner that is influenced by the local DNA sequence. Some DNA se- quences even permit the double helix to twist in the left-handed sense, as opposed to the right-handed sense originally formulated for DNA’s general structure. And while some DNA molecules are linear, others are circular. Still additional complexity comes from the supercoiling (further twisting) of the double helix, often around cores of DNA-binding proteins.
Likewise, we now realize that RNA, which at first glance appears to be very similar to DNA, has its own distinctive structural features. It is principally found as a single-stranded molecule. Yet by means of intra-strand base pairing, RNA exhibits extensive double-helical character and is capable of folding into a wealth of diverse tertiary structures. These structures are full of surprises, such as non-classical base pairs, base-backbone interactions, and knot-like configurations. Most remarkable of all, and of profound evolutionary significance, some RNA molecules are enzymes that carry out reactions that are at the core of information transfer from nucleic acid to protein.
Clearly, the structures of DNA and RNA are richer and more intricate than was at first appreciated. Indeed, there is no one generic structure for DNA and RNA. As we shall see in this chapter, there are in fact vari- ations on common themes of structure that arise from the unique physi- cal, chemical, and topological properties of the polynucleotide chain
What is the best-known feature of sedimentary
rocks?
A. ripple marks
B. fossils
C. graded bedding
D. cross-bedding
Answer:
option is (b)
Explanation:
please mark me as brilliant
An atom has 8 protons, 8 neutrons and 9 electrons. is thus a cation, anion, or neutral atom?
Answer:
It is an Anion because there are more electrons than protons making it negative
A sample of 87.6 g of carbon is reacted with 136 g of
fluorine gas to produce carbon tetrafluoride. Using
the balanced equation below, predict which is the
limiting reactant and the maximum amount in moles
of carbon tetrafluoride that can be produced.
C +2F2 → CF4
A. fluorine, 1.79 moles
B. carbon, 7.29 moles
C. fluorine, 6.72 moles
D. carbon, 4.63 moles
Answer:
A. fluorine, 1.79 moles
Explanation:
Given parameters:
Mass of carbon = 87.7g
Mass of fluorine gas = 136g
Unknown:
The limiting reactant and the maximum amount of moles of carbon tetrafluoride that can be produced = ?
Solution:
Equation of the reaction:
C + 2F₂ → CF₄
let us find the number of the moles the given species;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
C; molar mass = 12;
Number of moles = [tex]\frac{87.7}{12}[/tex] = 7.31moles
F; molar mass = 2(19) = 38g/mol
Number of moles = [tex]\frac{136}{38}[/tex] = 3.58moles
So;
From the give reaction:
1 mole of C requires 2 moles of F₂
7.31 moles of C will then require 2 x 7.31 moles of F₂ = 14.62moles
But we have 3.58 moles of the F₂;
Therefore, the reactant in short supply is F₂ and it is the limiting reactant;
So;
2 moles of F₂ will produce mole of CF₄
3.58 moles of F₂ will then produce [tex]\frac{3.58}{2}[/tex] = 1.79moles of CF₄
The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed below. Which of these elements is in this group?
Characteristics of a group of elements
•is shiny
•is solid at room temperature
•has atoms with two valence electrons
A-silicone
B-lithium
C-strontium
D-aluminum
Answer:
C:Strontium
Explanation:
Explain the humoral theory
Answer:
The medical philosophy of the ancient Greeks in which the state of health and disease was determined by the four body “humours”—blood, yellow and black bile, and phlegm—and their relationships with the four elemental humours—air, fire, earth and water. Segen's Medical Dictionary.
Explanation: