Final answer:
Potassium has an atomic number of 19, which means there are 19 protons in the nucleus of a potassium atom.
Explanation:
The atomic number of an element, such as potassium, is defined as the number of protons in the nucleus of an atom of that element. Since potassium has an atomic number of 19, there are 19 protons in the nucleus of a potassium atom. Additionally, this atomic number also means that a neutral atom of potassium would have 19 electrons. The electron configuration code for potassium, reflecting the arrangement of these 19 electrons in different shells or energy levels, can also be determined based on its atomic number.
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.
Five strategies needed by learners to acquire knowledge and skills to make informed decisions and take appropriate actions to ensure availability of clean water
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.What happens to matter if we add or take away energy
These substances are made up of two or more elements chemically combined?
Circle the term that does not belong in each of the following groups: KCl NaCl NaHCO3 MgSO4
True or false a homogeneous mixture is a mixture in which it is difficult to distinguish the substances from one another
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.
how many mg are there in a 5.00 grain aspirin tablet ? 1 grain = 0.00229 oz . there are 454 g/lb
To convert the mass of a 5.00-grain aspirin tablet to milligrams, convert grains to ounces, ounces to grams, and grams to milligrams. A 5.00-grain aspirin tablet is approximately 324.56 milligrams.
Explanation:The question is asking to convert the mass of a 5.00-grain aspirin tablet into milligrams. Since 1 grain is equal to 0.00229 ounces, we first need to convert ounces to grams and then to milligrams. We know that there are 28.3495 grams in an ounce, and 1 gram is equal to 1000 milligrams.
First, convert 5.00 grains to ounces:
5.00 grains * 0.00229 oz/grain = 0.01145 oz
Next, convert 0.01145 ounces to grams:
0.01145 oz * 28.3495 g/oz = 0.324555675 grams
Lastly, convert grams to milligrams:
0.324555675 g * 1000 mg/g = 324.555675 mg
Therefore, a 5.00-grain aspirin tablet is approximately 324.56 milligrams.
Is toasting marshmallows over a campfire a physical or chemical change?
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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If this reaction uses 34 grams of sodium and produces 72 grams of sodium chloride. what mass of chlorine was used?
Matter that is composed of two or more different elements chemically combined in a fixed proportion is classified as...
2. You have 2 m3 of a mineral ore sample. It has a mass of 1 × 104 kg. Calculate the density of the ore sample and express your results in g/cm3 with appropriate scientific notation.
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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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
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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how many traditional areas of study can chemistry be divided into
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.Is a substance that a filter can seperate into two parts a mixture or a pure substance?
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.
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.
Energy is expended when a force moves matter across a distance.
True
False
The conservation of mass-energy and the first law of thermodynamics are synonymous.
True
False
Temperature and thermal energy are synonymous terms.
True
False
On the Kelvin scale, temperatures are expressed as positive values only.
True
False
The amount of heat transfer required to change the temperature of one gram of water one degree Celsius is also known as a calorie.
True
False
What causes a substance to not be able to be broken down by chemical change?
If an isotope has an atomic number of 8 and a mass number of 18 how many neutrons
One liter of a solution ph 9 has how many more hydroxide ions (oh-) than 1 l of a solution of ph 4?
A solution with a pH of 9 has 100,000 times more hydroxide ions than a solution with a pH of 4 due to the corresponding pOH values and hydroxide ion concentrations based on the relationship between pH and pOH.
Explanation:The student has asked about the difference in the number of hydroxide ions between a solution with a pH of 9 and another with a pH of 4. Using the relationship PH + pOH = 14, we can find the pOH.
For the pH 9 solution, the pOH would be 5 (14 - 9), which corresponds to a [OH-] of 1.0 × 10-5 M. For the pH 4 solution, the pOH would be 10 (14 - 4), corresponding to a [OH-] of 1.0 × 10-10 M. Hence, the pH 9 solution has 1.0 × 10-5 M of OH-, which is 100,000 times greater than the 1.0 × 10-10 M OH- in the pH 4 solution.
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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Need help for the last questions!
Which group contains elements whose atoms have six electrons in their valence shell?