Answer:
Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A. The name comes from the fact that the oxides of these metals produced basic solutions when dissolved in water, and they remained solids at the temperatures available to the ancient alchemists. Like the Group 1A elements, the alkaline earth metals are too reactive to be found in nature in their elemental form.
The alkaline earth metals have two valence electrons in their highest-energy orbitals (ns2). They are smaller than the alkali metals of the same period, and therefore have higher ionization energies. In most cases, the alkaline earth metals are ionized to form a 2+ charge.
The alkaline earth metals have much higher melting points than the alkali metals: beryllium melts at 1287ºC, magnesium at 649ºC, calcium at 839ºC, strontium at 768ºC, barium at 727ºC, and radium at 700ºC. They are harder metals than the Group 1A elements, but are soft and lightweight compared to many of the transition metals.
Salts of the Group 2A metals are less soluble in water than those of Group 1A because of the higher charge densities on the 2+ cations; nevertheless, many Group 2A salts are at least moderately soluble. Some Group 2A salts bond strongly to water molecules, and crystallize as hydrates; among these are Epsom salt, MgSO4·7H2O, and gypsum, CaSO4·2H2O.
Explanation:
Answer:
H2, N2, O2, F2, Cl2, Br2, I2
Explanation:
The 7 diatomic elements in the periodic table are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine and Iodine.
Please help me.
a 750 sample of technetium-99 decays in 4 half lifes, how much of the sample will remain?
Answer:
93.75
Explanation:
In first half life 750×1/2 will remain
In second one half from that remained at the end of first half life will remain
That is 1/2 × 750×1/2
likewise at the end of 3rd half life 1/2 × 1/2 ×750×1/2 remains
at the end of 4th half life 1/2 × 1/2 × 1/2 ×750×1/2 remains
1/2 × 1/2 × 1/2 ×750×1/2 = 93.75 remains.
You can also use the equation
Remainder = X × 1/2^n .
This saves time
n= no. of half lives
X= initial amount
so in this case 1/2^4 × 750 = 93.75
Please help I’m soo confused what do you think might account for these similar properties? Explain
Answer:
i wonder...................
Explanation:
When a person goes on a diet, do they really want to lose weight or mass?
Need answer asap
Answer:
Cutting calories will help you lose weight. But dieting alone can strip away muscle along with body fat. Research suggests that as much as 25 per cent of weight lost by dieters is from muscle. And that's not a good thing.
Explanation:
How does the structure of compounds determine the properties of the compounds?
Answer:
All of these properties are due to the chemical structure of the compound. The chemical structure includes the bonding angle, the type of bonds, the size of the molecule, and the interactions between molecules. Slight changes in the chemical structure can drastically affect the properties of the compound.
Explanation:
Hope it helps.
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what is the answer ??z???????
Answer:
Females
Explanation:
Hope that helps
Answer:
The answer may be no characters
If I'm right or wrong plz reply to me
Choose the statement that is TRUE. Question 26 options: Outer electrons efficiently shield one another from nuclear charge. All of the answers are true Valence electrons are most difficult of all electrons to remove. Core electrons effectively shield outer electrons from nuclear charge. Core electrons are the easiest of all electrons to remove.
The statement which is true is Core electrons effectively shield outer
electrons from nuclear charge.
Core electrons are those which are in close proximity with the nucleus. The
core electrons repel the outer electrons farther away from the nucleus to
shield it from nuclear charge.
The valence electrons are usually found in the outermost part of the shell
and they are the easiest to remove due to the fact that they have to achieve
a stable octet configuration which makes them easily removed during
chemical reactions.
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Answer: core electrons effectively shield outer electrons from nuclear charge
Explanation:
Notice that the bond strength for lithium bonded with any of the anions is larger than the bond strength of potassium bonded with any of
the same anions. Propose a scientifically sound explanation for this.
Select one:
O a. Lithium comes before sodium or potassium alphabetically, so its bond will be stronger.
O b. Sodium and potassium are essential for human metabolism, so they should not bond as strongly with anions.
Oc. Lithium is the smallest cation, so bond length is shorter creating a tighter bond.
Od Lithium is the only cation with a +1 charge.
Check
The bond strength for lithium bonded with any of the anions is larger than the bond strength of potassium bonded with any of the same anions because lithium is the smallest cation, so bond length is shorter creating a tighter bond.
The strength of an ionic bond ultimately depends on the size of the ions. The smaller the ions the stronger the bond and the higher the lattice energy. Such compounds having a high lattice energy tend to deviate from the normal behavior of ionic crystals due to significant covalent contribution.
Lithium is the smallest cation in group 1. Hence, the bond strength for lithium bonded with any of the anions is larger than the bond strength of potassium bonded with any of the same anions because lithium is the smallest cation, so bond length is shorter creating a tighter bond.
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Which would best describe the way an organism reacts to other organisms or to its
environment?
A. Instinct
B. Behavior
C. Conditioning
D. Imprinting
Answer:
Explanation:
Behavior
I NEED THE ANSWER ASAP! Its science btw
Which statement describes conditions in which a mineral can form?
A. Crystals of minerals dissolve in the groundwater in caves.
B. Materials dissolved in seawater crystallize on an ocean bottom.
C. Molten materials are cooled in a netalworks factory
D. Materials are mined from deposits deep underground.
Answer:
b
Explanation:
which of the following best describes the relation ship between oxygen and chlorine
A. Oxygen and chlorine have the same symbols
B. Oxygen atoms have fewer protons than chlorine atoms
C. Oxygen and chlorine have the same properties
D. Oxygen atoms have twice as many protons as chlorine atoms
Answer:
B
Explanation:
The oxygen atoms have fewer protons than chlorine atoms:) hope this helps:))
According to the electronic configuration, oxygen atoms have fewer protons and electrons than chlorine atoms.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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4.16 Unit Test: Chemical Bonding - Part 2 1. You are studying alkaline earth metals bonding with Halogens. Using your knowledge of the ionic bonding, what specific and testable scientific question could be asked about the salt formation
A testable scientific question could be asked about the salt formation is; "Is the salt soluble in water?
A scientific question is a question that can be answered by experiments. In other words, a scientific question must be empirical. Its answer can only be obtained by carrying out experiments.
In the case of bonding in alkaline earth metals, the kind of bond formed is ionic. Ionic compounds are soluble in water. Hence, a testable scientific question could be asked about the salt formation is; "Is the salt soluble in water?
This can be answered by dissolving several salts of alkali earth metals in water.
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How can you classify matter?
Answer:
Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. A chemical substance is composed of one type of atom or molecule.
Hope this helps :)
Write the net ionic equation for the reaction that occurs, if any, when gold is placed in a solution of hydrobromic acid
Answer:
ionic salt MX2
Explanation:
Atoms from an element in group IIA are allowed to react with atoms from an element in group VIIA. What type of compound is likely to form
elements from IIA are alkali earth metals (M) and need to lose
2 e^1- to become stable as M^2+
elements from VIIA ar halogens (X) and need to gain 1 e^1-
to become stable so one M^2+ combines with 2 X^1- to make
an ionic salt MX2
A student was performing paper chromatography and let the separation continue overnight. The
A student was performing paper chromatography and let the separation continue overnight. The student wished to determine if the mixture contained a substance with an RF factor of 0.343 where:
Rf = (distance travelled by the component)/(distance travelled by the solvent)
a) What data would be affected by this error?
b) Explain the effect on the calculated Rr.
Based in the information given, the data that'll be affected by the error is the value of the solvent data.
It should be noted that the data that'll be affected based on the scenario given is the value of the solvent. When the preparation is kept overnight, there'll be an overflow of the solvent.
In such a case, it'll be difficult to get the correct distance that the solvent travelled. The effect on the calculated Rr is that the calculated Rr will be incorrect due to the error in solvent value.
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Explain, in terms of particles, what happens when methane boils and why
the boiling point of methane is lower than that of butane.
Answer:Butane > ethane > methane, because between bigger molecules there are stronger van der Waals forces and also higher molar mass means they need to be given more energy to have enough kinetic energy to move quickly, freely in gas.
There are multiple butene isomers (Butene) and some (2-Butenes - cis and trans) actually have higher boiling point than n-Butane (there is also Isobutane, of course, with quite much lower boiling point than all of them) and some (1-Butene, Isobutylene) have lower, so this isn't really a fair or simple question. But on simplest level, it can again be said that 1-butene has lower boiling point because it has very similar shape but slightly lower molar mass (2H less) than n-butane.
Explanation:
Intermolecular forces such as dipole-dipole forces, London dispersion forces exist between molecules and these depend on strength of electronegativity of molecule. Therefore, methane converts to gas on boiling due to weak intermolecular forces of attraction between the molecules.
What is intermolecular forces of attraction?Intermolecular forces of attraction is force of attraction that make two molecule come closer. Intermolecular forces of attraction is directly proportional to the electronegativity of the molecule.
Size of electronegative molecule is small so, if any other molecule or molecule come into contact with this molecule then this molecule attract the electron of other molecule very efficiently and therefore the force between the molecule increases.
Molecules of methane have weak intermolecular forces of attraction. When energy is applied, the methane molecules easily break apart and turn into gas.
Therefore, methane converts to gas on boiling due to weak intermolecular forces of attraction between the molecules.
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Convection currents are one force driving plate tectonics. What other force plays a major role?
Heat transfer
Gravity
Radioactive decay
Fossil formation
Answer:
Gravity
Explanation:
Gravity was founded by famous physician Sir Izak Newton.The gravity is a phenomenon by which every object in the universe attracts eachotherNewton discovered gravity by the falling apple from tree.The following factors contribute to plate tectonics: The Mantle's Convection. Mountain push gravitational force at the spreading ridges, Block pull gravitational force in subduction zones. Hence, option B is correct.
What is gravitational force ?The gravitational force, which is what pushes mass-containing objects toward one another. We frequently consider the pull of gravity from the Earth. Your body is kept on the ground by this force. However, all mass-bearing objects are pulled toward one another by gravity.
Population growth and changes in people's wants and activities are the main causes behind this. Changes in the overall levels of output and consumption are caused by these main movers.
The driving forces put strain on the environment through these modifications to production and consumption. In the direction of motion, gravity produces an active driving force.
Thus, option B is correct.
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Which element has 12 protons 12 neutrons and 12 electrons
Answer:
Magnesium
Explanation:
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure.
How many atoms of lithium are there in 18.2mg of lithium? Dimensional analysis only!
Answer:7.25
Explanation:
This is because 18.2 - 7.2 = 11 +7.2 = 18.2
What are the major reservoirs for sulfur
Answer:
the ocean, the ocean floor basalts, evaporite deposits and reduced marine sediments.
Explanation:
describe how fluids exert forces on objects
Explanation:
Fluids exert forces on objects because of many molecules of the fluid that continuously collide with the surfaces of the object immersed in the fluid. Squeezing a plastic mustard bottle forces mustard out the top because of the amount of force or pressure applied to it that results in mustard coming out.
When an object is immersed in a fluid, the fluid exerts an upward force known as buoyancy. The buoyant force is caused by the fluid's pressure on the object.
How does fluids exert forces on objects?The upward force exerted by fluids on all matter is known as buoyant force. Force According to Archimedes' principle, the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid that the object replaces or displaces.
A submerged object's buoyant force is equal to the weight of the fluid displaced. By measuring the mass of an irregularly shaped object, this principle can be used to determine its volume and thus density.
Squeezing a plastic mustard bottle forces mustard out the top due to the amount of force or pressure applied to it, which causes mustard to come out.
Thus, Fluids exert forces on objects because their molecules constantly collide with the surfaces of the objects immersed in the fluid.
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Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions: Ca2+, Al3+, Cl−, O2−
Answer:
CaCl2
CaO
Al2O3
AlCl3
You can do this by swapping the values of charges on the ions as below
eg- Ca2+ - 2
Cl- - 1
Now combine 1 Ca atom and 2 Cl atoms and it will give you CaCl2
Al 3+ - 3
O2- - 2
Combine 2 atoms of Al and 3 atoms of O
Al2O3
In the case of CaO, we have to make sure that the atoms are in their simplest ratio. So although we get Ca2O2, CaO is the correct form
What is called exothermic
An exothermic process is one that gives off heat.
Explanation:
This heat is transferred to the surroundings. An endothermic process is one in which heat has to be supplied to the system from the surroundings.
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because: __________
a. cobalt is a stronger reducing agent than iron
b. iron is a stronger reducing agent than manganese
c. cobalt exhibits more metallic character than either iron or manganese in the iron-manganese alloy
Rusting is an electrochemical reaction. Iron rusts faster when alloyed with cobalt than when alloyed with manganese because, in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
An alloy is a combination of two metals. There are various reasons for producing alloys such as greater tensile strength, corrosion resistance and improved aesthetic appearance.
When iron is alloyed with cobalt, the iron rusts faster than pure iron because iron is rendered the anode and cobalt is rendered the cathode. When the iron is alloyed with manganese, it rusts more slowly than pure iron because in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode.
Missing parts;
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because
(1) cobalt is a stronger reducing agent than iron
(2) iron is a stronger reducing agent than manganese
(3) cobalt exhibits more metallic character than either iron or manganese
(4) in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
(5) in the iron-cobalt alloy, cobalt is rendered the anode and iron is rendered the cathode
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If you have 1 mol xe and 1 mol f₂, how many moles of xef₄ can you create in the following chemical reaction? xe (g) 2 f₂ (g) → xef₄ (g).
The number of moles of XeF4 that can be created would be 0.5 moles.
From the equation of the reactiobn:
Xe (g) 2 F₂ (g) ---> XeF₄ (g)
The mole ratio of Xe to F2 is 1:2. Hence, in the presence of 1 mole Xe and 1 mole F2, F2 would be limiting the reaction.
This means that the amount of F2 would determine the amount of XeF4 that would be produced from the reaction.
The mole ratio of F2 to XeF4 according to the equation is 2:1. This means that for every 1 mole of F2 introduced into the reaction, 0.5 moles of XeF4 will be produced.
In this case, 1 mole of F2 is introduced. Thus, the mole of XeF4 that would be produced would be:
1/2 = 0.5 moles.
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14 In which group are all the elements found
naturally only in compounds?
(1). 18
(3) 11
(2) 2
(4) 14
When we lower the temperature of the solvent, the rate of dissolving of the solute will....?
Answer:
Decrease
Explanation:
An increase in temperature would increase the dissolution rate and a decrease in temperature would decrease the dissolution rate
Answer:
The rate of dissolving of the solute will increase I think
discuss the solubility differences between the halogens and the halides in both hexane and water. be sure to define what a halogen and halide are to foundation your discussion.
Halides are ionic substances while halogens nonpolar substances. Hence, halides dissolves in water while halogens dissolve in hexane.
A halogen is an element in group seventeen. The name halogen means salt former. This name came about because many of the halogens form salts. Halides are salts formed by the halogens.
Halogens are diatomic covalent molecules. As such, they are nonpolar molecules and can only effectively interact with nonpolar solvents. Benzene is a nonpolar solvent hence it acts as an effective solvent for the halogens.
The halides are polar compounds hence they do not dissolve in nonpolar solvents such as hexane. Rather, halides dissolve in polar solvents such as water due to dipole - dipole interaction between the ions in the halide and the dipoles in water.
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Question: How can NASA scientists use Newton's third law of motion to plan for a space vehicle landing on a meteor? Make a claim. Support your claim with evidence from the article. Then, explain why the evidence supports your claim.
Article: https://newsela.com/read/lib-newton-third-law/id/54749/
Answer:
Explanation:
NASA uses rockets to launch astronauts and supplies to the International Space Station. Launching a rocket relies on Newton's Third Law of Motion. A rocket engine produces thrust through action and reaction. The engine produces hot exhaust gases which flow out of the back of the engine
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29.0 argon combine completely with 4.30 g of Sulfur.
Calculate the percent compositions of the compounds that are formed from the reaction
Answer:
33.3
Explanation:
if we were to add 29.0 of argon and 4.30 of sulfur and that would come out 33.3.
if the column of water in the water barometer rose to a height of 36 feet, what would the atmospheric pressure be in mm hg?
The Atmospheric pressure is usually constant and is; 760mm Hg.
According bro the question;
The column of water in the water barometer rose to a height of 36 feet.The absolute pressure is given as;
P(abs) = P(atm) + P(gauge)The gauge pressure is dependent on the height of the water column.
Ultimately, the atmospheric pressure is constant and is given as; 760mm Hg.
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