Carbon = C
Water = C
Aluminum foil = E
Plastic = E
Tin = E
Silicon dioxide = C
Helium = C
Arsenic = C
Carbon dioxide = C
Sodium Chloride = C
What action is the best example of a direct observation
Answer:
The best example of direct observation is when the researcher of animal behavior directly observe how animal lives in a reservation.
Which element has 7 valence electrons and 3 electron shells?
From the following list of symbols, choose two elements that would likely form a
molecular compound. Explain your choice.
Mg:
S:
K:
O:
Help plzz
Answer:
O ( Oxygen )
because oxygen atom is a non metal and highly electronegative which reacts by itself to form a di-molecular compound of Oxygen
[tex]O _{2}[/tex]
How many molecules are present in 98.2g of NaNO3
6.96 × 10²³ molecules NaNO₃
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
98.2 g NaNO₃
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of Na - 22.99 g/mol
Molar Mass of N - 14.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of NaNO₃ - 22.99 + 14.01 + 3(16.00) = 85.00 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 98.2 \ g \ NaNO_3(\frac{1 \ mol \ NaNO_3}{85.00 \ g \ NaNO_3})(\frac{6.022 \cdot 10^{23} \ molecules \ NaNO_3}{1 \ mol \ NaNO_3})[/tex]Multiply: [tex]\displaystyle 6.95718 \cdot 10^{23} \ molecules \ NaNO_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
6.95718 × 10²³ molecules NaNO₃ ≈ 6.96 × 10²³ molecules NaNO₃
Density is defined as mass per unit volume, or D = m/v. Solve the density
equation for the variable v: *
v = D + m
v = D/m
v = D * m
v= m/D
Answer:
v = m/D
Explanation:
Density is defined as the mass per unit volume, or D = m/v. Solve for Density equation for the variable v:
With this we are making v Which represents volume the subject so;
[tex]d = \frac{m}{v} [/tex]
With this you multiply both sides by ;
[tex]v[/tex]
[tex]v(d) = ( \frac{m}{v})v[/tex]
And then the v will multiply the d making it
“vd” and the ‘v’ will cancel the v making it;
[tex]vd = m[/tex]
So then we divide both sides by d to make v the subject.
[tex] \frac{vd}{d} = \frac{m}{d} [/tex]
So the d cancels the d leaving;
[tex]v = \frac{m}{d} [/tex]
True or false. The center of gravity and center of mass of an object need to be in the same spot?
Answer:
True................
Answer:
true
Explanation:
25 cm3 of 0.2 mol / dm3 sodium hydroxide (NaOH) neutralises 10 cm3 of dilute sulfuric
acid (H2SO4). What is the concentration of the sulfuric acid?
Answer:
too simple question i don't have book pen now otherwise solved it
How many hydrogen atoms are present in 25.3 g of C3H8 (propane)? How many carbon atoms?
please help :(
Answer:
27.65×10²³ atoms of H
10.37×10²³ atoms of C
Explanation:
Given data:
Mass of C₃H₈ = 25.3 g
Number of hydrogen atom = ?
Number of carbon atom = ?
Solution:
Number of moles of propane:
Number of moles = mass/molar mass
Number of moles = 25.3 g/ 44.1 g/mol
Number of moles = 0.574 mol
1 mole of propane contain 3 mole of carbon atoms.
0.574 moles of propane contain 0.574 × 3 mol = 1.722 moles of C.
1 mole = 6.022 ×10²³ atoms of C
1.722 mole × 6.022 ×10²³ atoms of C / 1 mol
10.37×10²³ atoms of C
Number of atoms of H:
1 mole of propane contain 8 mole of hydrogen.
0.574 moles of propane contain 0.574 × 8 mol = 4.592 moles of H.
1 mole = 6.022 ×10²³ atoms of H
4.592 mole × 6.022 ×10²³ atoms of H / 1 mol
27.65×10²³ atoms of H
When a nitrogen atom covalently bonds to three hydrogen atoms to form ammonia, it still retains one pair of unshared electrons.
According to VSEPR theory, what is the shape of an ammonia molecule?
OA. linear triatomic
OB. tetrahedral
OC
pyramidal
OD. trigonal planar
Answer:
C. Trigonal pyramidal
Explanation:
According to the valence shell electron pair repulsion theory, the shape of ammonia is trigonal pyramidal in nature.
The bond angle is 107° and it has bond pair of 3 and lone pair of 1.
The variations in the bond angles of molecules can be explained by the VSEPR model. This model determines the total number of electron pairs surrounding the central atom of a specie.A tetrahedral is exhibited by methane
Trigonal planar is exhibited by BF₃
What compound is missing?
3Na2SO4 + 2AlCl3 →+ _____ + 6NaCl
Answer:
Al2(SO4)3
Explanation:
3Na2SO4 + 2AlCl3 →+ Al2(SO4)3 + 6NaCl
When an experiment is repeated and the new results are different from the original results what may likely be inferred?
A)
Additional test/trials are needed.
B)
Both results are wrong due to the discrepancy.
C)
The hypothesis is incorrect and must be modified.
D)
The first must be inaccurate because you are sure the second results
are correct.
Answer:
A ) additional test/trial are needed
Elephant heart cells have 56 chromosomes. Elephant egg cells have
28 chromosomes
112 chromosomes
56 chromosomes
16 chromosomes
Answer:
28 chromosomes
Explanation:
The elephant egg cells will have just half of the original number of chromosomes which is 28 chromosomes.
The other zygote which is the male sperm will also contain 28 chromosomes.
Reproductive cells the egg and the sperm contains a haploid number of cells. During fertilization the cells combine to form a complete diploid where both the male and female genetic material are replicated. This way half of the original chromosome number are taken through to the sex cells.
15 grams of hydrogen and 7.5 grams of oxygen were placed in a beaker. An explosion happened inside the baker that produced water. The beaker was never opened. How many grams of water were produced?
Answer:
16.8768 g
Explanation:
The reaction that takes place is:
2H₂ + O₂ → 2H₂OFirst we convert the mass of hydrogen and oxygen into moles, using their respective molar masses:
H ⇒ 15 g ÷ 1 g/mol = 15 mol HO ⇒ 7.5 g ÷ 16 g/mol = 0.4688 mol OThere are significantly less oxygen moles than hydrogen moles, so oxygen is the limiting reactant.
We calculate the produced moles of water, using the moles of the limiting reactant:
0.4688 mol O * [tex]\frac{2molH_2O}{1molO_2}[/tex] = 0.9376 mol H₂OFinally we convert water moles into grams, using its molar mass:
0.9376 mol H₂O * 18 g/mol = 16.8768 gsimilar scientific themes are seen in what areas of science?
A. only in areas dealing with living things
B. in all areas of science
C. only in areas dealing with tinny particles
D. only in areas dealing with things on Earth
Answer:B
Explanation:
5.6 x 10^3 cm = ___cg
Answer:
560000 cg
Explanation:
5.6 x 10^3 = 5600
1 g = 100 cg
5600 g = 560000 cg
What happens to sound waves when you are moving toward the source of the
sound?
A. Wavelength increases.
B. Wave speed decreases.
C. Amplitude decreases.
D. Frequency increases.
Answer:
B
Explanation:
CTL
Carlos Almanza
ke'
COL TEACHING LEAD
144%
21. Which of the following is not a transformation from chemical energy to thermal
energy?
a, Coal is burned to boil water
b. An electric stove cooking food
C. Food is digested to regulate body temperature
d. Charcoal is burned in a grill
22. During most energy transformations some energy is transformed and released as
which of the following forms of energy?
Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid (HCNO) and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of solution.
Ka(HCNO) = 2.0 x 10^-4
The pH of a buffer solution : 4.3
Further explanationGiven
0.2 mole HCNO
0.8 mole NaCNO
1 L solution
Required
pH buffer
Solution
Acid buffer solutions consist of weak acids HCNO and their salts NaCNO.
[tex]\tt \displaystyle [H^+]=Ka\times\frac{mole\:weak\:acid}{mole\:salt\times valence}[/tex]
valence according to the amount of salt anion
Input the value :
[tex]\tt \displaystyle [H^+]=2.10^{-4}\times\frac{0.2}{0.8\times 1}\\\\(H^+]=5\times 10^{-5}\\\\pH=5-log~5\\\\pH=4.3[/tex]
Help, please, I really need it.
Answer:
CO(g) + H2O(g) ⇌ CO2(g) + H2(g)
Lisa wants to determine which melts faster, an ice cube or a popsicle. What procedure should she follow to conduct her experiment?
A.
Set an ice cube equal in size to a popsicle at room temperature, and time how long it takes each to melt.
B.
Set an ice cube and a chocolate popsicle at room temperature, and time how long it takes each to melt.
C.
Set any ice cube and any popsicle at room temperature, and time how long it takes each to melt.
D.
Set an ice cube and an orange popsicle at room temperature, and time how long it takes each to melt.
What is indicated by a letter in parentheses after a chemical
formula, such as (s)?
a) whether the reaction is fast or slow
b) the purity of the substance
c) the physical state of the substance
d) that the substance is a catalyst
The letter in parentheses after a chemical formula indicates c) the physical state of the substance.
The letters can be:
→ (s) for solid.
→ (l) for liquid.
→ (g) for gazeous.
→ (aq) for an aqueous solution (like NaCl (aq) - NaCl is dissolved in water)
what is p³×p simplify
Answer:
The answer is p⁴.
Explanation:
You have to apply Indices Law :
[tex] {a}^{m} \times {a}^{n} ⇒ {a}^{m + n} [/tex]
For this question :
[tex] {p}^{3} \times {p}^{1} [/tex]
[tex] = {p}^{(3 + 1)} [/tex]
[tex] = {p}^{4} [/tex]
the relative atomic mass of hydrogen is Ar (H) = 1008.Calculate the absolute mass of a hydrogen atom
Answer:
im good but mark brainliest
Explanation:
Answer:
i don think thats what she ment
Explanation:
A scientist named J. J. Thomson developed a model of the atom in which electrons are spread throughout a cloud of positive charge. Which discovery directly caused scientists to revise this model?
Answer:
A small mass of positive charge was discovered in the center of the atom.
Explanation:
Atoms is the combination of protons, neutrons, as well as electrons particles. The particles that are in the centre of atom is Protons and neutrons, which made up the nucleus, this nucleus is surrounded by electron.
The discovery that directly caused scientists to revise this model of the atom is that A small mass of positive charge known as proton, and a positive charge particle was discovered by Ernest Rutherford, in the center of the atom in the year 1900. Ernest Rutherford through his research resulted to splitting of the atom during nuclear reaction and proton was discovered.
How can a conceptual model be used to develop a testable hypothesis? Select one: a. Conceptual models cannot be used to develop a testable hypothesis. b. Conceptual models help us see how things are related and how they connect or work together. This helps us develop a hypothesis based on changes in a variable and the corresponding response of another variable. c. Conceptual models are never revised once they are made. d. Conceptual models are not based prior observations and are guesses used to generate a hypothesis.
Answer:
b. Conceptual models help us see how things are related and how they connect or work together. This helps us develop a hypothesis based on changes in a variable and the corresponding response of another variable.
Explanation:
A conceptual model refers to a vivid representation or conceptualization of the working of a system. Hence conceptual models offer explanations to ideas about systems.
They help to fit all the facts together so that one can make sense of a system. Also, it helps us to understand how changes in one variable affects the other in a system, thereby helping us to formulate a testable hypothesis.
1. The forks shown are made of silver (Ag). Some of the silver forks
shown have lost their luster—they have become tarnished. This is an
example of Type here.
Pleasee help
Answer:
Corrosion
Explanation:
Silver is known as a noble metal. Noble metals are those metals that are resistant to corrosion.
However, we can not say that silver is completely resistant to corrosion because silver can corrode when exposed to air and sulphur.
Exposure to air and sulphur leads to the coating of the silver with a sulphide layer thereby making the metal to become tarnished and loose its metallic luster.
Which of the following is a characteristic of reliable scientific study? (5
points)
Answer:I need the options
Explanation:
what is the realationship between chemicals and cancer
Answer:
Explanation:
"An early link between cancer and a chemical was found in the late 1700s. An English physician noted that a large number of chimney sweeps had cancer of the scrotum due to exposure to soot, which contains chemicals known as polycyclic aromatic hydrocarbons. Since then, many more chemicals have been identified as known or suspected causes of cancer. "
Answer:
Chemical cause cancer
Explanation:
The overall force acting on an object after all the forces are combined is _________
force?
Answer:
Hi... Your answer is total force
A group of Chemistry students have 1.0 mole each of two mystery substances, Substance X and Substance Y, at 50° C. Explain why a conclusion about the kinetic energy of each substance is not possible. (Write in short answer form--- 3-5 sentences)
Answer:
The temperature of a substance in chemistry, is taken as a measure or estimate of the average kinetic energy ([tex]K_{avg}[/tex]) of the atoms or molecules contained in the substance. The 6.02 × 10²³ particles (atoms or molecules) within 1.0 mole of each substance can each posses different amount of kinetic energy at any given time. Some particles move very fast while others move very slow such that the kinetic energy of all the particles are only representable by a distribution and a conclusion regarding the different aspects of the kinetic energy distribution of the particles of the substances is not easily possible
Explanation:
For a gas, we have;
[tex]KE_{avg} = \dfrac{3}{2} \cdot k \cdot T[/tex]
Where;
[tex]KE_{avg}[/tex] = The average kinetic energy
k = 1.38 × 10⁻²³ J/K
T = The gas temperature in Kelvin