Which group contains elements whose atoms have six electrons in their valence shell?
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The mass number of an atom is equal to which of the following?
Question 4 options:
A.the number of protons plus the number of electrons in an atom
B.the number of electrons circling the nucleus of an atom
C.the number of protons plus the number of neutrons in a nucleus
D.the number of protons in a nucleus
the answer is c, the number of protons plus the number of neutrons in a nucleus
Is toasting marshmallows over a campfire a physical or chemical change?
What elements in the periodic table might combine with oxygen to form magnesium oxide?
Magnesium combines with oxygen to form magnesium oxide, which is characterized by the chemical formula MgO. The reaction is facilitated by the burning of magnesium in the presence of oxygen. This reaction highlights magnesium's strong affinity for oxygen.
Explanation:The element from the periodic table that combines with oxygen to form magnesium oxide is magnesium. This is derived from the chemical formula for magnesium oxide, which is MgO. Here, Mg represents magnesium and O represents oxygen. The reaction to create magnesium oxide typically occurs when magnesium is burnt in the presence of oxygen, as illustrated by the chemical reaction: 2Mg(s) + O₂(g) → 2MgO(s). This reaction shows that magnesium and oxygen combine to form magnesium oxide.
Magnesium is recognized for its potency in chemical reactions, particularly in those involving oxides. When magnesium burns, it reacts with carbon dioxide to produce elemental carbon, demonstrating magnesium's significant affinity for oxygen.
Moreover, many of the common salts of the alkaline earth metals like magnesium are insoluble in water due to their high lattice energies and these compounds' divalent metal ions.
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Is a substance that a filter can seperate into two parts a mixture or a pure substance?
What is the concentration of nitrate ions in a 0.225 msr(no3)2 solution?
We are given that there are 2 moles of NO3 from the 0.225 M Sr(NO3)2 solution. Therefore we simply use stoichiometry to solve this problem.
Concentration NO3 = 0.225 M Sr(NO3)2 * (2 moles NO3 / 1 mole Sr(NO3)2)
Concentration NO3 = 0.45 M
Answer : The concentration of nitrate ions is 0.450 m.
Solution : Given,
Molarity of [tex]Sr(NO_3)_2[/tex] = 0.225 m
The balanced ionic equation is,
[tex]Sr(NO_3)_2\rightarrow Sr^{+2}+2NO^-_3[/tex]
From the reaction, we conclude that the 1 mole of [tex]Sr(NO_3)_2[/tex] produces 2 moles of [tex]NO^-_3[/tex] ions. That means the concentration of nitrate ions is twice the value of [tex]Sr(NO_3)_2[/tex].
then, 0.225 m of [tex]Sr(NO_3)_2[/tex] gives 2 × 0.225 of [tex]NO^-_3[/tex] ions
Now the concentration of [tex]NO^-_3[/tex] ions is equal to 0.450 m.
chemistry
how do you count atoms?
4 HNO3
To count atoms in 4 HNO3, the coefficient 4 is multiplied with the number of each type of atom. It results in 4 hydrogen atoms, 4 nitrogen atoms, and 12 oxygen atoms.
To count atoms in a chemical formula like 4 HNO3, you look at the coefficients and subscripts. The coefficient (4 in this case) tells us how many molecules of HNO3 there are. We multiply this by the number of each type of atom within one molecule. Nitric acid (HNO3) has one hydrogen (H), one nitrogen (N), and three oxygen (O) atoms. Therefore, to count the atoms in 4 HNO3, we do the following: 4 molecules of HNO3 each contain 1 H atom, giving us a total of 4 H atoms; 4 molecules have 1 N atom each which is a total of 4 N atoms; and 4 molecules each have 3 O atoms, resulting in 12 O atoms in total. So, 4 HNO3 contains 4 hydrogen atoms, 4 nitrogen atoms, and 12 oxygen atoms.
Circle the term that does not belong in each of the following groups: KCl NaCl NaHCO3 MgSO4
In the periodic table of elements, some elements share similar properties and have the same number of valence electrons in their outer shell. what do we call these type of elements in the periodic table of elements.
These substances are made up of two or more elements chemically combined?
California’s rice fields are _______.
a.
visited by migrating waterfowl
b.
flooded during the summer
c.
a source of wild bird meat
d.
all of the above
Answer:
a just took the test on engenuity
Explanation:
hope dis helps : p
California’s rice fields are visited by migrating waterfowl. Hence option a is correct.
What is migration?Migration is defined as movement from one nation, location, or neighborhood to another in quest of greater chances for settling. The primary beneficial consequences of migration on host countries are the growth of the labor force, the diversification of cultures, the filling of skill gaps in the labor market, and the improvement of local economies. Differences in income and economic opportunities between nations, varied levels of social and human security, and preexisting ethnic and diaspora networks are the main drivers of international migration.
Waterfowl are birds with waterproof feathers and webbed feet that can swim well. They propel themselves through the water by using their webbed feet as flippers. Waterfowl frequently have webbed feet, rounded bodies, long necks, and short wings. Near water bodies, waterfowl typically build their nests on the ground. Some are an exception to this rule, such as the Common Merganser and Wood Duck, which lay their eggs in nest boxes or cavities in trees.
Thus, California’s rice fields are visited by migrating waterfowl. Hence option a is correct.
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Five strategies needed by learners to acquire knowledge and skills to make informed decisions and take appropriate actions to ensure availability of clean water
Is boron nitride a compound element or mixture?
What happens to matter if we add or take away energy
how many traditional areas of study can chemistry be divided into
Write the formula for barium nitrite. write the formula for barium nitrite. bn ba(no2)2 ba3n2 b(no2)3 bano3
The formula for Barium nitrite is Ba(NO₂)₂. This is because barium has a +2 charge and nitrite has a -1 charge, so two nitrite ions are needed to balance the charge of the barium ion. So correct option is a.
a) Ba(NO₂)₂.
Barium nitrite is a chemical compound formed by the combination of the elements barium (Ba) and nitrite (NO₂). To understand the formula of barium nitrite, let's break down the composition of the compound:
1. Barium (Ba):
Barium is a metallic element with the chemical symbol "Ba." It belongs to the alkaline earth metal group, which is located in group 2 of the periodic table. Barium is a highly reactive metal that readily forms compounds with other elements.
2. Nitrite (NO₂):
Nitrite is a polyatomic ion composed of one nitrogen atom (N) and two oxygen atoms (O). Its chemical formula is NO₂. Nitrite is negatively charged due to the presence of two extra electrons, which gives it a -1 charge.
The chemical formula of barium nitrite is Ba(NO₂)₂.
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At what temperature would 250 ml of water boil? 1000 ml? is the boiling point an intensive or extensive property? explain.
Final answer:
The boiling point of water is 100°C and is an intensive property because it does not change with the amount of water. Intensive properties do not vary with the quantity of substance, while extensive properties do.
Explanation:
The boiling point of a substance is the temperature at which it changes from a liquid to a gas. For water, this temperature is 100°C under standard atmospheric pressure (1 atm). Whether we have 250 ml or 1000 ml of water, the boiling point remains the same and is an example of an intensive property. This is because intensive properties do not depend on the amount of substance present.
Regarding extensive and intensive properties, temperature is an example of an intensive property because it does not change when the amount of substance is doubled. On the other hand, an extensive property is dependent on the amount of substance (e.g., volume or mass). Combining two samples of water with the same temperature will result in a mixture of the same temperature, demonstrating that temperature is intensive.
When considering the ratio of two extensive properties, such as mass to volume to obtain density, the resultant property is intensive because it characterizes the property per unit amount, therefore not changing with the quantity of substance.
If an isotope has an atomic number of 8 and a mass number of 18 how many neutrons
If this reaction uses 34 grams of sodium and produces 72 grams of sodium chloride. what mass of chlorine was used?
Does the density of ice affect the melting rate of ice, or does adding objects affect melting rates? I'm going to need evidence of some kind. If not, that's okay.
What causes a substance to not be able to be broken down by chemical change?
The bond length in f2 is 1.417 å, instead of twice the atomic radius of f, which is 1.28 å. what can account for the unexpected length of the fuf bond?
Final answer:
The bond length in[tex]F_{2}[/tex] is shorter than expected due to electron-electron repulsion and the influence of molecular orbitals, which lead to a bond length that doesn't simply equate to twice the atomic radius of fluorine.
Explanation:
The bond length in [tex]F_{2}[/tex] is shorter than twice the atomic radius of F because of electron-electron repulsion within the molecule. The process of bond formation involves not just the attraction between the electrons and nuclei but also the repulsion between the nuclei themselves and the electron pairs. When two fluorine atoms approach each other, their unpaired electrons in their outermost shells pair up to form a covalent bond, and due to fluorine's high electronegativity and small size, there is significant repulsion between these electrons when they are in close proximity. Additionally, when considering bond lengths, it is important to note that molecular orbital theory and experimental data both play a role in understanding the nature of bonds. The molecular orbital theory, which considers both bonding and antibonding orbitals, predicts a single bond for [tex]F_{2}[/tex] as confirmed by the experimental bond order. Therefore, the combination of these repulsive forces and the nature of the molecular orbitals involved results in a bond length that is shorter than the sum of two fluorine atomic radii.
True or false a homogeneous mixture is a mixture in which it is difficult to distinguish the substances from one another
Repulsion between closely packed protons in the nucleus is overcome by
Answer:
Strong nuclear force
Explanation:
As we know that positive charges repel each other so protons do repel each other although atoms are stable because of strong nuclear force acting between nucleons (protons and neutrons in nucleus are called nucleons) which overcome the repulsive force between the proton. Strong nuclear force is very short-range force and acts only in distance of angstrom or picometre.
In each vertical column, or group, of the periodic table, the elements have ____.
a. similar chemical and physical properties
b. different chemical and physical properties
c. similar physical but different chemical properties
d. different physical but similar chemical properties
In each vertical column or group of the periodic table, elements have similar physical and chemical properties.
What is periodic table?Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.
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A dynamic state where two opposing forces are in balance, where two opposite events are occurring at equal rates is _____.
Equilibrium
Explanation;Equilibrium is a dynamic state where two opposing forces are in balance, where two opposite events are occurring at equal rates. The building process is equal in rate to the tearing-down process.There are two types of equilibrium; dynamic equilibrium and static equilibrium.Dynamic equilibrium occurs when reactants are converted to products and products are converted to reactants at an equal and constant rate, which means the rate of forward reaction is equal to the rate of backward reaction.Static equilibrium occurs when particles in the reaction are at rest and there is no motion between reactants and products. When a substance changes its state, all BUT ONE of these statements is true. That is
A) Mass remains constant.
B) Only the form changes.
C) Kinetic energy changes.
D) Something new is formed.
Answer:
D . Something new is formed.Explanation:
The option A, B and C are true statement while D is false statement.
Mass remains constant.
During a physical change mass remain constant, just state change.Only the form changes.
During a physical change ,just state changeKinetic energy changes.
During a physical change ,kinetic energy also change because liquid, solid and gases have different inter molecular forces which relate to K.E.Something new is formed.
when substance change state, then it remained as such as before, just its state change, not composition.How many moles of atoms are in 7.00 g of 13c? express your answer numerically in moles?
There are 0.538 moles of ¹³C atoms in the given 7.00 g sample.
Further ExplanationThis is a simple mole conversion problem. It requires the molar mass, or the mass of one mole of a substance, of carbon - 13, an isotope of carbon. An isotope is like a different version of a specific atom. In this case, carbon - 13 is a version of a carbon atom that has one more neutron than the normal carbon atom. It is a little heavier than the normal carbon atom because of its extra neutron.
Converting Mass to MolesTo convert from grams of sample to moles of sample, the general equation is:
[tex]moles \ of \ sample = \frac{given \ mass}{molar \ mass}[/tex]
To convert 7.00 g of ¹³C, the equation is:
[tex]mole \ of \ ^{13}C \ = \frac{7.00 \ g}{13.00 \ \frac{g}{mol}} \\\boxed {mole \ of \ ^{13}C \ = 0.53846 \ mol}[/tex]
Since there is only 3 significant figures in the given, the final answer must also have 3 significant figures. Therefore,
[tex]\boxed {\boxed {mole \ of \ ^{13}C \ = 0.538 \ mol \ or \ 5.38 \times 10^{-1} \ mol}}[/tex]
This answer is logical since one mole of ¹³C will have a mass of 13.00 g. The given sample (7.00 g) is less than 13.00 g so the mole equivalent of that should be less than one mole.
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