化学
化学反応、化学量論、分子構造、元素の性質。
-
write the symbol for every chemical element that has atomic number less…
N, O, F, Ne, Na, Mg
-
write the symbol for every chemical element that has atomic number grea…
\(Se, Br, Kr\)
-
12 verdadero o falso 1 punto erlenmeyer flasks are not accurate measuri…
1. **Question 12**: True 2. **Question 13**: the temperature measured in Kelvin 3. **Question 14**: - Particles are arranged in an organized way: Solid - Variable volume: Gas - Pa…
-
complete the following table for isotopes. symbol # protons # neutrons …
## 4. | Symbol | # Protons | # Neutrons | Atomic Number | Mass Number | | ---- | ---- | ---- | ---- | ---- | | $^{60}_{28}Ni$ | 28 | 32 | 28 | 60 | | $^{40}_{19}K$ | 19 | 21 | 19 …
-
topic #3: atomic structure, ions, and isotopes to learn atomic structur…
### 1. a. Protons: 29, Electrons: 27 b. Protons: 14, Electrons: 14 c. Protons: 7, Electrons: 10 d. The ion formed by oxygen is usually $O^{2 - }$. Protons: 8, Electrons: 10 ### 3.…
-
classify the substance shown in the sketch below. you can click the oth…
solid, mixture, heterogeneous mixture
-
a chemist working as a safety inspector finds an unmarked bottle in a l…
Calculate the density of the liquid: $0.626\ g\cdot cm^{-3}$ Given the data above, is it possible to identify the liquid?: yes If it is possible to identify the liquid, do so.: pe…
-
topic #3: atomic structure, ions, and isotopes to learn atomic structur…
1. a. Protons: 29, Electrons: 27 b. Protons: 14, Electrons: 14 c. Protons: 7, Electrons: 10 d. Oxygen forms \(O^{2 -}\), Protons: 8, Electrons: 10 2. First row: \(La^{3+}\), Proto…
-
17 lesquels des composés suivants nexistent pas? explique tes réponses.…
Les composés qui n'existent pas sont NaK et LiNe.
-
element # protons # neutrons # electrons mass number type your answer..…
| Element | # protons | # neutrons | # electrons | Mass Number | | ---- | ---- | ---- | ---- | ---- | | F | 9 | 10 | 9 | 19 | | N | 7 | 8 | 7 | 15 | | O | 8 | 8 | 8 | 16 |
-
read the descriptions below of two substances and an experiment on each…
Is sample A made from a pure substance or a mixture? mixture Is sample B made from a pure substance or a mixture? pure substance
-
atomic symbols a is the mass number: total number of protons + neutrons…
1. **For the isotope table**: - For the first row with \(p^{+}=6\) and \(n^{0}=6\), the mass number \(A=p^{+}+n^{0}=6 + 6=12\), and the symbol is \(\ce{^{12}_6C}\) - For the secon…
-
osha 10 hour construction: module 11 - health hazards in construction e…
D. Both a and b
-
osha 10 hour construction: module 11 - health hazards in construction e…
B. Safety Data Sheets (SDSs)
-
question 1 of 10 oshas hazard communication standard (hazcom) is design…
C. Hazardous chemicals
-
verification de tes hypotheses 1 retourne à lexploration de la page 4 e…
1. Un atome est la plus petite partie d'un élément avec ses propriétés, une molécule est formée de plusieurs atomes. 2. Nombre atomique, masse atomique, propriétés chimiques et ph…
-
5 referring to figure 1, notice that water shows capillary attraction, …
Mercury has weak adhesion to glass and strong cohesive forces among its own molecules, while water has strong adhesion to glass, which leads to different meniscus shapes.
-
maximum protection from on - the - job noise is provided by _____. * ea…
1. C. earplugs used with earmuffs 2. B. measure the concentration of hazardous chemicals
-
6 observe limage ci - dessous. quelle est la masse de loxygène? 7 compl…
## Question 6 La masse de l'oxygène est égale à la masse de 16 atomes d'hydrogène. ## Question 7 éléments, atomes, numéro atomique, masse atomique, carbone ## Question 8 ### a) FA…
-
workers should know where a shower is located in case they are splas wi…
1. True 2. move to a cool area
-
1. lequel de ces énoncés est vrai? coche la bonne réponse. a. la masse …
B. Le tableau périodique évolue au fil des découvertes scientifiques. 2.
-
matter can exist in several different forms which are called solids liq…
phases
-
1. lequel de ces énoncés est vrai? coche la bonne réponse. a. la masse …
A. La masse atomique est la mesure de la taille d'un atome. 2.
-
which would make water impure? adding chemicals adding ice
adding chemicals
-
which is a nonchemical method for cleaning a floor? using a mop and ble…
using a broom and dustpan
-
4. lesquels de ces énoncés sappliquent au modèle atomique de dalton? co…
A. Le corps humain est composé de divers atomes. D. Dalton a pu élaborer son modèle atomique sans avoir vu un atome. E. Selon le modèle de Dalton, les atomes sont indivisibles. F.…
-
03 pratique 1 vrai ou faux? lorsquun énoncé est faux, corrige - le. a) …
a) Faux b) Faux c) Vrai 2.
-
1. why do isotopes of the same element have different masses? 2. what w…
1. Isotopes of the same element have different masses because they have different numbers of neutrons. 2. Cannot be answered without more data. 3. Approximately 39.56% 4. Closer t…
-
draw the correct lewis structure of scl₂. be sure to include all lone p…
The Lewis structure has a sulfur atom in the center, single - bonded to two chlorine atoms. Each chlorine atom has 3 lone - pairs of electrons and the sulfur atom has 2 lone - pai…
-
identify the correct lewis structure for ch₃cho. select the single best…
The first structure (with the carbon - carbon single bond, carbon - oxygen double bond and appropriate hydrogen atoms and lone pairs on oxygen).
-
the graph shows that as the temperature of the water increases, the tim…
Making tea/coffee (using hot water to dissolve sugar faster); Cleaning greasy dishes (hot water dissolves grease faster)
-
identify the correct lewis structure for nf₃. select the single best an…
The first structure (where N is single - bonded to three F atoms and each atom has its full complement of lone - pairs) is the correct Lewis structure for NF₃.
-
a dietician asks a patient about the food that the patient eats and mak…
The patient should decrease the amount of rice and pasta and increase the amount of oils in his or her diet.
-
question time! when a molecule has more than one interior atom, _____. …
more than one geometry may be used to describe the molecule
-
the goal of the vsepr model is to arrange the position of the atoms and…
C. repulsion
-
question time! __________ atoms always obey the octet rule. o oxygen, c…
Oxygen, fluorine, nitrogen, carbon
-
question time! the octet rule is based upon the observation that atoms …
D. 8
-
an example of an atom with 3 valence electrons is _____. ○ sodium ○ mag…
C. aluminum
-
allotropes are _. ○ molecules bonded through the sharing of valence ele…
B. different structural modifications of an element
-
figure 1. allotropes of the element carbon. a. crystalline structure of…
A. sharing of valence electron pairs
-
determine the correct molecular geometry based on the number of bonds a…
| Bonds | Lone pairs | Geometry | | ---- | ---- | ---- | | 2 | 2 | Bent | | 3 | 0 | Trigonal planar | | 3 | 1 | Trigonal pyramidal | | 4 | 0 | Tetrahedral |
-
one piece of evidence for the daltons atomic theory is the observation …
D. a compound always has the same proportions of different elements.
-
which theory includes that all elements consist of tiny particles that …
A. atomic theory
-
select the correct term to complete each statement. - allotropes - duet…
1. VSEPR 2. duet 3. allotropes 4. structures 5. electron deficient 6. valence electrons
-
match the number of valence electrons with the correct compound. ch₄ pb…
CH₄: 8 PBr₃: 26 OF₂: 20 CH₂O: 12 O₃: 18 SiCl₄: 32
-
question 9 6 pts which of the following is a nonpolar molecule? o h2s o…
Question 9: B. $CO_2$ Question 10: A. $CH_4$
-
question 7 6 pts a nonpolar covalent bond will form between which two a…
- Question 7: chlorine and chlorine - Question 8: increases.
-
question 5 6 pts in any period, the highest electronegativity is found …
Question 5: nonmetal Question 6: hydrogen and chlorine
-
question 3 6 pts co is called monocarbon monoxide carbon oxide carbon m…
Question 3: carbon monoxide Question 4: nonpolar covalent
-
question 1 6 pts the prefix \hepta\ means six. true false question 2 6 …
Question 1: B. False Question 2: A. N₂O
-
for the reaction 3a + 4b → 2c + d, what is the magnitude of the rate of…
\(3.2\ M/min\)
-
for the reaction 2a + 3b → 4d + 5e, how is the rate of reaction express…
A. \(\frac{\Delta[B]}{\Delta t}\) is incorrect because the rate of disappearance of B has a negative sign. B. \(-\frac{\Delta[B]}{\Delta t}\) represents the rate of disappearance …
-
which small molecule neurotransmitter is in a class all by itself? mono…
Question 20: D. acetylcholine Question 21: C. catecholamines, E. indolamines
-
12. refer to the hydrogen isotopes in model 1. each isotope has a speci…
12. The names refer to the number of neutrons in the atom. 13. No. Isotopes are of the same element with different neutron numbers. If mass numbers are the same and they are the s…
-
what is the one class of large molecule neurotransmitters? acetylcholin…
B. neuropeptides
-
draw the lewis structure for n₂br₂ molecule. be sure to include all lon…
The Lewis structure has two N atoms in the middle with a single bond between them. Each N is single - bonded to a Br atom. Each Br has 3 lone - pairs of electrons and each N has 1…
-
arrange the following bonds in order of decreasing ionic character: mg …
Li - N, Mg - N, Si - C
-
four atoms are arbitrarily labeled d, e, f, and g. their electronegativ…
DG < EG < DF < DE
-
arrange the following bonds in order of increasing ionic character: pot…
nitrogen to chlorine, bromine to hydrogen, sodium to chlorine, potassium to oxygen
-
list the following bonds in order of decreasing ionic character: the li…
Li - F > Na - I > P - Cl > H - S
-
for the elements rb and br, please indicate whether the binary compound…
Ionic; RbBr; Rubidium bromide
-
extension questions 11. determine the number of electrons in each of th…
a. The number of electrons is equal to the number of protons in a neutral atom. b. It is important because it ensures the atom has a net charge of zero, making it electrically neu…
-
art-111-z191 2025fa - art appreciation / module 5 september 15 - 21 / c…
A. All of the above
-
art-111-z191 2025fa - art appreciation / module 5: september 15 - 21 / …
e. patina
-
draw the lewis dot symbol for as.
As with 2 dots on one side and 1 dot on each of the other three sides around the symbol.
-
question 10 please match the key word to the correct definition. column…
1. Chemical reaction - g. a process that transforms two different sets of chemicals into a new set of chemicals when they come in contact with one another 2. Endothermic reaction …
-
use the images below to answer the question. the images show a beaker o…
d. Molecules of dye moved by diffusion from a higher concentration to a lower concentration.
-
show instructions question 1 a. h2n - c - c - oh r b. ch2oh ch2oh o ho …
B. Option B
-
a 53.81 gram sample of copper is heated in the presence of excess oxyge…
$Cu_2O$
-
a 5.775 - gram sample of iron is heated in the presence of excess chlor…
FeCl₃
-
an alcohol is 58.80 % c and 9.889 % h by mass. the rest is oxygen. what…
$C_5H_{10}O_2$
-
use the references to access important values if needed. the percent by…
$61.18$
-
use the references to access important value. calculate the percentage …
Mass percentage of nitrogen = 30.43% Mass percentage of oxygen = 69.57%
-
the percent by mass of copper(ii) in cu(no2)2 is %.
$40.85$
-
1. how many grams of k⁺ are present in 4.73 grams of potassium nitrate?…
1. 1.83 g 2. 5.51 g
-
use the references to access important values if needed for this questi…
a. $8.12\times 10^{22}$ atoms b. $6.71$ g
-
part 3a 12 marks choose 4 of 5 (lesson 3a) draw the following ionic bon…
a) Formula: $Li_3P$; Ionic - bond drawing: 3 $Li^+$ around 1 $P^{3 -}$ with electron - transfer arrows. b) Formula: $CaCl_2$; Ionic - bond drawing: 1 $Ca^{2+}$ with 2 $Cl^-$ aroun…
-
1. how many grams of barium chloride are present in 4.08 moles of this …
1. 850.57 grams 2. 0.0225 moles
-
safety with materials a chemical purchased in canada. (sds) must be pro…
1. To provide hazard and safety - related information for chemicals. 2. Chemical substances, mixtures, and some chemical - containing products. 3. Categorized into multiple sectio…
-
part 2d 3 marks choose 3 of 4 (lesson 2b) draw the lewis dot diagrams o…
a) Po with 6 dots around it b) Rn with 8 dots around it c) Sr with 2 dots around it
-
1. how many grams of sodium chloride are present in 2.39 moles of this …
1. 139.6716 2. 0.0385
-
carbon monoxide gas can be described as all of the following except col…
B. visible
-
use the references to access important values if needed for this questi…
A sample of Ga weighs less than 60.7 grams. Mass = 53.4 g Ga
-
working with various chemicals... - if any part of your body comes in c…
- If any part of your body comes in contact with a substance, wash it immediately and thoroughly with water. - If you get anything in your eyes, do not touch them. Wash them immed…
-
what chemical group is highlighted in pink in the molecule pictured bel…
Hydroxyl
-
contaminated by foreign substances occurs when what’s on my food? milk …
Chemicals are not rinsed from foods before processing
-
q1. physical properties can be observed and measured without changing t…
Q1: D. All of the above Q2: C. Flammability Q3: D. Mass Q4: A. Chemical property
-
all ionic compounds 1. write the formula for each compound (don’t forge…
1) $Ca(C_{2}H_{3}O_{2})_{2}$ 2) $KCl$ 3) $(NH_{4})_{2}CO_{3}$ 4) $Na_{3}N$ 5) $Ti(ClO)_{4}$ 6) $Fe_{2}S_{3}$ 7) $ZnCr_{2}O_{7}$ 8) $PtO_{2}$ 9) $Al(OH)_{3}$ 10) $Hg(NO_{3})_{2}$ 1…
-
herbicides are not considered as chemical hazards. do you also eat thes…
False
-
for a chemistry demonstration, malik is mixing sodium hydroxide with vi…
D. \(4x+6y\leq0\)
-
which refers to the amount of heat required to change the temperature o…
B. Specific heat
-
heat is most closely related to which kind of energy? nuclear electrica…
C. thermal
-
heat transfer between two substances is affected by specific heat and t…
amount of time and area of physical contact between the substances.
-
in this section, you learned that all body matter is eventually replace…
1. Our body's matter - replacement shows we are part of biogeochemical cycles, exchanging elements. 2. Reducing fossil - fuel use, reforestation. 3. Increased evaporation, altered…
-
in this section, you learned that all body matter is eventually replace…
1. Our body's matter replacement indicates our active role in biogeochemical cycles. 2. Reducing fossil - fuel consumption, Planting more trees. 3. Increased evaporation, altered …
-
question 5 (2 points) what is the net ionic equation for the reaction o…
$Fe^{2+}(aq)+CO_3^{2 - }(aq) ightarrow FeCO_3(s)$
-
question 4 (2 points) which of the following is a precipitation reactio…
$\text{Pb}(\text{C}_2\text{H}_3\text{O}_2)_2(\text{aq})+2\text{NaCl}(\text{aq}) ightarrow\text{PbCl}_2(\text{s}) + 2\text{NaC}_2\text{H}_3\text{O}_2(\text{aq})$
-
question 3 (2 points) which of the following pairs of aqueous solutions…
LiOH + CuBr2
-
question 2 (2 points) which of the following compounds is not soluble i…
PbCl₂
-
question 1 (2 points) which of the following compounds is soluble in wa…
$Na_3PO_4$