化學
化學反應、化學計量、分子結構與元素性質。
-
what is the mass (in grams) of 2 moles of antimony? 243.52 g 121.76 g 6…
243.52 g
-
question 3 what is the coefficient of carbon dioxide, co₂, when the fol…
8
-
what is the molar mass of mercury(ll) nitrate? 324.61 g/mol 246.60 g/mo…
324.61 g/mol
-
question 1 which of the following reactions is a double - replacement r…
\(\text{Mg(OH)}_2(s)+\text{H}_2\text{SO}_4(aq) ightarrow 2\text{H}_2\text{O}(l)+\text{MgSO}_4(aq)\)
-
multiple - choice question 11. the name for making the dots for the val…
A. The Lewis Dot Diagram
-
multiple - choice question 10. what do hydrogen, lithium and sodium hav…
C. They all have one electron in the outer most shell or valence
-
8. the second energy level can hold how many electrons? eight one rewat…
Eight
-
6. atomic number refers to what subatomic particle? neutron proton elec…
Proton
-
6. read the following sentences: \when the atoms of a specific substanc…
C. qualities or characteristics
-
3. what are the circles referred to that electrons are demonstrated in …
Both Energy Levels or Shells
-
3. table salt can be separated into sodium and chlorine. sodium is expl…
B. A harmless compound can become harmful when its elements are separated.
-
multiple - choice question 2. what is on the outside of the atom? elect…
Electrons
-
1. what is found in the nuclei of an atom? protons and neutrons neutron…
Protons and Neutrons
-
name: date: 1. what happens when the atoms of a substance are regrouped…
C. a new substance is formed
-
10. iron is extracted from the mineral magnetite, fe₃o₄: fe₃o₄(s) + 2 c…
The percentage yield of the reaction is approximately \(59.3\%\)
-
what is a major way ionic and covalent or molecular compounds differ? i…
ionic compounds transfer or steal electrons while covalent compounds share electrons
-
methanol is in liquid form if its temperature is between -93.9°c and 64…
\(-43^{\circ}C\), \(0^{\circ}C\), \(25^{\circ}C\)
-
which type of compound will break apart into individual atoms when diss…
ionic
-
which type of compound makes a more organized structure? both ionic cov…
ionic
-
multiple - choice question what type of compounds form positive and neg…
B. ionic
-
multiple - choice question which statement about ionic bonding is true?…
one atom can steal electrons from another
-
multiple - choice question in ionic compounds, electrons are transferre…
shared
-
multiple choice question what is another name for the chemical compound…
silica
-
place each of the labels into the proper category to indicate whether t…
- Hydrophilic: Ions, \(K^{+}\), Polar compounds, Carbohydrates - Hydrophobic: Lipids, Cholesterol
-
chemists use integers to express the electrical charge of particles. a …
\(-7\)
-
chemists use integers to express the electrical charge of particles. a …
\(4\)
-
3. below are two different lewis structures for c₂h₆o. are both structu…
Both structures are correct. They are called isomers (functional group isomers). The first structure is ethanol (an alcohol), and the second structure is dimethyl ether (an ether).
-
which of the following activities will result in chemicals easily reach…
Smoking a cigarette, Drinking vodka, Taking brain cancer medications orally, Eating a high - glucose meal, Wearing an oxygen mask.
-
multiple-choice question true or false? compounds can have more than 2 …
True
-
multiple - choice question what element is a nonmetal but located over …
B. hydrogen
-
multiple - choice question what is another name for covalent compounds?…
molecular
-
question 1 1 pts which of these correctly shows the group of atoms and/…
\(Cu > Cu^{+}>Cu^{2+}\) (the third option in the given choices)
-
fill in the blank question chemical messengers secreted by endocrine or…
hormones
-
why are microwaves, but not radio waves nor ultraviolet (uv) waves, use…
A microwave has a lower frequency and carries less energy than a UV wave. But the quanta of energy carried by a microwave causes water and fat molecules to vibrate and produce hea…
-
a sample of tin (cp = 0.227 j/g·°c) is placed in a freezer. its tempera…
$95.7$
-
a cube of iron (c = 0.450 j/g·°c) with a mass of 55.8 g is heated from …
$603\ J$
-
use the specific heat values to answer the following questions. which o…
C. $H_2O(l)$
-
use the specific heat values to answer the following questions. which o…
\(3.0\space g\space Pb\) has the smallest heat capacity.
-
for electromagnetic waves traveling in a vacuum, we can substitute \\( …
Infrared wave: \(7.79\times 10^{-23}\space J\) Visible light: \(3.20\times 10^{-19}\space J\) X - ray: \(3.54\times 10^{-16}\space J\)
-
h₂o 18.02g/mol ch₄ 16.05g/mol h₂co₃ 62.03g/mol c₆h₁₂o₆ 180.18g/mol acti…
\(5.25\space mol\)
-
h₂o 18.02g/mol ch₄ 16.05g/mol h₂co₃ 62.03g/mol c₆h₁₂o₆ 180.18g/mol acti…
\(5.25\space mol\)
-
1. an ionic bond is a. attraction of an atom for its electrons. b. attr…
C. a force that holds together atoms that are oppositely charged.
-
why are microwaves, but not radio waves nor ultraviolet (uv) waves, use…
A. Ultraviolet (UV) wave has a higher frequency and carries more energy than a microwave. But the quanta of energy carried by a microwave causes water and fat molecules to vibrate…
-
determine whether each statement is true or false. all electromagnetic …
- All electromagnetic waves travel through air at the same constant speed: True. - All electromagnetic waves travel at the speed of light: True. - The frequency and wavelength of …
-
ionic compounds and metals section 7.1 ion formation in your textbook, …
1. chemical bond 2. nucleus 3. electrons 4. ions 5. valence 6. energy level 7. noble gases 8. octet 9. pseudo - noble gas formations
-
2. draw a lewis structure for each of the following. a. hbr b. cl
H : Br : (with three lone pairs on Br)
-
4. calculate: if the units are correct, multiply or divide the numbers …
\(5.25\) moles For part B, since the user has to check against the "Show numerical result" (which we assume would show \(5.25\) if the calculation above is correct), if the calcul…
-
which type of sense organ is specialized to monitor the position and mo…
proprioceptors
-
calculate the ph from each $h_{3}o^{+}$ concentration. your answer part…
Part 1 of 2: \(pH = 3.17\) Part 2 of 2: \(pH = 2.14\)
-
calculate the ph of each aqueous solution. round each of your answer to…
- Part 1 of 2: \(pH = 4.75\) - Part 2 of 2: \(pH=12.48\)
-
calculate the ph from each $h_{3}o^{+}$ concentration. part 1 of 2 $lef…
- Part 1 of 2: \(pH = 3.17\) - Part 2 of 2: \(pH = 2.14\)
-
get the gizmo ready: • check that the equation is still: fe₂o₃ + 3co → …
A. \(28.01u\) B. \(44.01u\) C. \(159.7u\) Molar mass: \(Fe_{2}O_{3}:159.7g/mol\), \(CO:28.01g/mol\), \(Fe:55.85g/mol\), \(CO_{2}:44.01g/mol\) Practice: \(H_{2}O:18.02g/mol\), \(CH…
-
gizmo warm - up just as a cook follows a recipe to decide how much of e…
1. \(Fe_2O_3\): \(1\); \(CO\): \(3\); \(Fe\): \(2\); \(CO_2\): \(3\) 2. Reactants - Iron: \(2\); Oxygen: \(6\); Carbon: \(3\) Products - Iron: \(2\); Oxygen: \(6\); Carbon: \(3\) …
-
what is the molarity of 0.500 l of naoh solution if it contains 6.00 g …
\(0.300\ M\)
-
5. suppose a bag full of ice (450 g) at 0.0 °c sits on the counter and …
\(100.2\space kJ\)
-
use with textbook pages 148 to 151. balancing chemical equations refer …
1. \(2\text{NI}_3 ightarrow\text{N}_2 + 3\text{I}_2\) 2. \( \text{Fe}_2\text{O}_3 + 6\text{HCl} ightarrow2\text{FeCl}_3+3\text{H}_2\text{O}\) 3. \(3\text{Zn}+\text{Cu}_3\text{N}_2…
-
10.** consider the following molecule, **so₂** a. draw the lewis struct…
A. Lewis structure: \(O = S - O\) (with lone pairs, bent geometry) B. Number of valence electrons: \(18\) C. Formal charges: Double - bonded \(O\): \(0\); Single - bonded \(O\): \…
-
yes. no, it has the wrong number of valence electrons. the correct numb…
No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are: \(H\)
-
yes. no, it has the wrong number of valence electrons. the correct numb…
Yes.
-
8. ** what hybridization change does the carbon atom undergo in the fol…
D. \(sp^{3}\to\) no hybridization
-
question 6 of 10 a database speeds up the sharing of scientific knowled…
A. assembling large amounts of information in a single location
-
cif₃ yes, its a reasonable structure. no, the total number of valence e…
No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: \(F\)
-
decide whether the lewis structure proposed for each molecule is reason…
- For \(O_3\): No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: \(O\) (central \(O\) and single - bonded \(O\)) - For \(SF_3^-\…
-
carlos is building models of different materials. he uses red beads for…
B. It shows an element made of only carbon atoms
-
a student proposes the following lewis structure for the isocyanate (nc…
| atom | formal charge | | ---- | ---- | | \( C \) | \(-1\) | | \( O \) | \(+1\) | | \( N \) | \(-2\) |
-
a student proposes the following lewis structure for the isocyanate (nc…
| atom | formal charge | | ---- | ---- | | \(C\) | \(-1\) | | \(O\) | \(+3\) | | \(N\) | \(-2\) |
-
how many valence electrons are in the trimethylammonium ion $(ch_{3})_{…
26
-
how many valence electrons are in the phosphorus tribromide molecule pb…
26
-
in each of the molecules drawn below one chemical bond is colored red. …
1. The highlighted \( H - N \) bond is polar and the more negative atom is \( N \). 2. The highlighted \( Br - Br \) bond is nonpolar. 3. The highlighted \( Cl - F \) bond is pola…
-
elements,elements in order of decreasing electronegativity,f,c,b,o,te,s
\(F > C> B\); \(O > S> Te\)
-
the table shows the number of students in each grade at prairie middle …
80
-
a chemist puts 2.969 liters of liquid in each of 66 beakers. how much l…
195.954
-
in science class, christina is told that the red solution has a density…
\(98.8\)
-
drag and drop the words or phrases that accurately complete the paragra…
1. created 2. transformed 3. potential 4. motion
-
if a -2 ion has 34 protons, what element is it? germanium (ge) selenium…
selenium (Se)
-
give the ion symbol for the ion that has 27 protons and 24 electrons.
\(Co^{3 +}\)
-
if an ion has 13 protons and 10 electrons, what is the charge on the io…
\(+3\)
-
how many protons would be found in the ion whose symbol is given below?…
8
-
consider the two reactions. 2nh₃(g) + 3n₂o(g) → 4n₂(g) + 3h₂o(l) δh° = …
$81.5$
-
structure of poetry quick check what is rhyme scheme? (1 point) ○ a set…
the ordered pattern of rhymes at the ends of lines of a poem
-
proposed lewis structure is the proposed lewis structure reasonable? ye…
- For \(:F = O = F:\): No, it has the wrong number of valence electrons. The correct number is \(19\). - For \(N - N\): No, it has the wrong number of valence electrons. The corre…
-
if a +1 ion has 29 protons, what element is it? silicon (si) nickel (ni…
copper (Cu)
-
if a +2 ion has 18 electrons, what element is it? argon (ar) calcium (c…
Calcium (Ca)
-
which energy transformation sequence best describes what happens when a…
chemical → electrical → sound
-
how is energy changing when a match burns? light energy changes to heat…
Chemical energy changes to light and heat energy.
-
what type of energy transformation is described above? mechanical energ…
mechanical energy changing into heat energy
-
a thermometer is placed in water in order to measure the waters tempera…
The molecules in the thermometer’s liquid spread apart.
-
look at the picture and then answer the question. when the lamp is turn…
light
-
raina tutors chemistry. for each hour that she tutors, she earns 30 dol…
150
-
when a battery is used to power a toy car, its chemical energy is trans…
electrical
-
how many electrons would be found in the ion whose symbol is given belo…
\(54\)
-
at which temperature does the motion of atoms and molecules stop? 0°c 0…
\(0\space K\)
-
jenny measures the temperature inside a cave to be 10°c. the temperatur…
less than
-
3. aluminum undergoes a synthesis reaction with oxygen to form aluminum…
- \(2.0\space mol\) of \(Al(s)\) and \(1.5\space mol\) of \(O_{2}(g)\) - \(0.60\space mol\) of \(Al(s)\) and \(0.45\space mol\) of \(O_{2}(g)\) - \(108\space g\) of \(Al(s)\) and …
-
atom, and answer the question below. all of the following are correct, …
Electrical energy is the movement of protons to create electricity.
-
practice it! which of the following are accurate examples of forms of e…
A. A lawn mower uses mechanical energy. D. A battery stores chemical energy. E. A hot cup of coffee contains thermal energy.
-
drag and drop the words or phrases that accurately complete the paragra…
1. potential 2. stored 3. kinetic 4. transformed
-
drag and drop the words or phrases that accurately complete the paragra…
1. cannot 2. kinetic 3. thermal (Note: Among the given options, if we assume a mis - label and consider the most relevant from the given, but strictly based on given options, if w…
-
which one of the following is the correct option for fill in the blank:…
mechanical
-
select the statement that is not accurate about the following energy tr…
Dante is using gravitational potential energy when walking to school.