Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
-
a mother finds her daughters mug of hot cocoa on a table an hour after …
The cocoa was mixed with hot water, but some cocoa settled as it cooled because the solubility went down
-
multiple choice 1point decide if each reaction is balanced or not balan…
Balanced
-
which statement is the best explanation for the graph? (1 point) as tem…
As temperature rises, gas particles are moving faster and may leave the solution
-
19 multiple choice 1 point a student mixes 4 grams of hydrogen with 32 …
36 grams
-
which option is a microscopic property that helps determine whether or …
polarity
-
which substance is an example of a nonpolar compound? (1 point) food co…
vegetable oil
-
what are the products in the following chemical equation? ch₄ + 2o₂ → c…
C. $CO_2 + 2H_2O$
-
which of the following molecules has the formula ch₂o? a o c=h o b h c=…
B.
-
16 multiple choice 1 point ca(oh)₂ + h₂so₄ → caso₄ + 2h₂o 140g? 165g 32…
57
-
ca(oh)_2 + h_2so_4 = caso_4 + 2h_2o 18.5g 3.2g how many grams of h_2so_…
$1.33$ (assuming the first option in the multiple - choice is $1.33$)
-
procedure 1|100.0 g|97.5 g procedure 2|100.0 g|102.5 g assuming the stu…
Procedure 1: One of the products was a gas that escaped into the air. Procedure 2: A gas from the air reacted with one of the other reactants.
-
element r has 3 isotopes: isotope atomic mass (amu) abundance (%) r - 3…
The missing abundance is 4.50%, and the average atomic mass of Element R is 35.409228 amu
-
unit 3 test - atoms and the periodic table 20. which picture is the boh…
d.
-
element q has the following isotopes: isotope atomic mass (amu) abundan…
$102.50$
-
element x has three isotopes: • x - 39: atomic mass = 38.96 amu, abunda…
$39.10$ amu
-
8 multiple choice 1 point what type of maintenance is the best way to r…
E. Water Change
-
element b has two isotopes: b - 35: atomic mass = 34.97 amu, abundance …
$35.45$
-
an unknown element has these isotopes: • a - 28: atomic mass = 27.98 am…
$28.09$
-
element z has the following isotopes: • z - 62: atomic mass = 61.93 amu…
$62.45$
-
unit 3 test - atoms and the periodic table 14. how many neutrons does t…
# Explicaciones paso a paso: ## Paso 1: Encontrar el número de protones de litio El número atómico del litio es 3, lo que significa que tiene 3 protones. ## Paso 2: Calcular el nú…
-
unit 3 test - atoms and the periodic table 14. how many neutrons does t…
# Explicación paso a paso: ## Paso 1: Encontrar el número de protones del litio El número atómico del litio es 3, lo que significa que tiene 3 protones. ## Paso 2: Calcular el núm…
-
multiple answer 4 points which of the following are transition metals? …
Tin, Titanium, Tungsten, Chromium, Silver, Zinc
-
atomic structure worksheet list the 3 subatomic particles, their charge…
| Element | Symbol | Atomic Number (Z) | Atomic Mass (A) (rounded) | # of Protons | # of Electrons | # of Neutrons | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | Sodium | …
-
questions 8-12: calculations. use the information below to answer the f…
$2.36\ g/mL$ ### Question 9
-
2 multiple choice 4 points which of the following shows a pair of halog…
C. F and Br
-
21 multiple choice 1 point what water quality chemical test would you p…
D. Salinity
-
7 test - atoms and the periodic table how many valence electrons does g…
# Explicación: ## Paso1: Nivel de valencia de los elementos del Grupo 13 Los átomos de los elementos del Grupo 13 tienen 3 electrones de valencia. ## Paso2: Número de electrones e…
-
balancing chemical equations - worksheet #1 balance the following chemi…
1. $2\text{Al}(s) + 6\text{HCl}(aq)=2\text{AlCl}_3(aq)+3\text{H}_2(g)$ 2. $2\text{K}(s)+2\text{H}_2\text{O}(l)=2\text{KOH}(aq)+\text{H}_2(g)$ 3. $3\text{Mg}(s)+\text{N}_2(g)=\text…
-
counting atoms practice identify the number of atoms for each element i…
| Compound | $Mg$ | $O$ | $H$ | $Ca$ | $C$ | $Ba$ | $P$ | $Fe$ | $N$ | $Cl$ | $Na$ | $S$ | $Sr$ | $F$ | $Cu$ | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---…
-
4. what is true about protons? a. are negative b. are positive c. are n…
4. b. Are positive 5. b. Transition Metals 6. b. Left
-
1 matching 4 points what groups are the following elements located in? …
Fr: Group 1; Ca: Group 2; P: Group 15; Sulfur: Group 16; Iodine: Group 17
-
14 multiple choice 1 point activated carbon charcoal granules absorb to…
# Breve explicación: La carbón activado actúa a través de un proceso químico al absorber químicos tóxicos como la amoníaco. Un filtro químico es aquel que utiliza reacciones quími…
-
3. which element is a cation? a. (p) phosphorous b. (ar) argon c. (bi) …
d. (Al) Aluminio
-
question 27 (1 point) which of the following is not a properties of wat…
C. Does not dissolve salt
-
which compounds have the empirical formula ch₂o? □ c₂h₄o₂ □ c₃h₆o₃ □ ch…
A. $C_2H_4O_2$, B. $C_3H_6O_3$, D. $C_5H_{10}O_5$, E. $C_6H_{12}O_6$
-
select all the correct answers. a compound has the percent composition …
To solve this, we need to calculate the percent - composition of each given formula and compare with the given percentages. 1. First, find the molar masses of elements: - Molar ma…
-
question 25 (1 point) cellobiose is formed from one alpha glucose and o…
D. Two Beta glucose
-
select all the correct answers. a compound has the percent composition …
Pd$(O_{2}CCH_{3})_{2}$, $Pd_{2}C_{8}H_{12}O_{8}$
-
type the correct answer in the box. tungsten carbide is becoming popula…
94
-
question 23 (1 point) which one is not van der walls forces london disp…
C. Hydrophilic
-
given 4al + 3o₂ → 2al₂o₃. in this chemical reaction, how many grams of …
708 g
-
how many atoms of oxygen are contained in 160 grams of n₂o₅? a. 1.27×10…
D. \(6.28\times 10^{24}\)
-
select the correct answer. given sno₂ + 2h₂ → sn + 2h₂o. tin oxide reac…
B. 4.21
-
how many particles are in one mole? a. 6.022×10^{23} b. 2.066×10^{23} c…
A. $6.022\times 10^{23}$
-
1 type the correct answer in the box. use numerals instead of words. gi…
5
-
aquariums mastery check show your mastery of the learning targets by co…
B. Ammonia
-
question 5. when setting up a pre - press profile, which color scheme i…
C. CMYK
-
19 logan had an ice pack on his swollen knee. most likely what receptor…
C. thermoreceptor
-
determine laquelle des configurations électroniques suivantes nest pas …
26) Valide 27) Invalide, l'orbital $3p$ est manquant. 28) Invalide, l'ordre d'occupation des orbitales est incorrect. 29) Valide 30) Valide
-
question 12 (1 point) which of the following is buffer comprise? a stro…
None of the given options are correct. A buffer is typically a weak acid and its conjugate base or a weak base and its conjugate acid.
-
question 11 (1 point) which of the following is not a type of intermole…
A. Covalent bond
-
question 7 which of the following best describes a molecule that is a h…
unsaturated fat
-
chemical energy is the energy stored in the chemical bonds that hold mo…
The statement in option A is incorrect as we get energy from the chemical energy stored in the food's chemical bonds, not from the kinetic energy of constantly moving molecules in…
-
according to the law of conservation of energy, energy cant be created …
A. there is a limited supply of them and we can't make any more.
-
using the four steps to critique artwork. 1. describe the artwork. 2. a…
How did the artist use vanishing point(s) and orthogonal lines?
-
hydrogen has three isotopes ^1h, ^2h, and ^3h. what is the difference b…
The number of neutrons ranges from 0 to 2.
-
in which orbitals would the valence electrons for selenium (se) be plac…
C. s orbital and p orbital
-
which of daltons ideas about the atom did j.j. thomsons experiment disp…
It disproved that atoms are indivisible.
-
which statement best describes how electrons fill orbitals in the perio…
Electrons fill orbitals in order of their increasing energy from left to right.
-
which element has 32 protons in its nucleus? phosphorus cobalt germaniu…
C. germanium
-
a single atom of an element has 11 protons, 11 electrons, and 12 neutro…
B. Na
-
who was the first to propose the existence of atoms? john dalton democr…
B. Democritus
-
4. a reference gives the density of calcium as 1.54 g/cm³. based on lab…
$18.83\%$
-
which best describes matter at the atomic level? a) submicroscopic b) m…
A. submicroscopic
-
who first identified the element radium? charles richard drew enrico fe…
D. Marie Curie
-
pictured above are three aluminum atoms. this time notice that there is…
There will be a flow to the left
-
mendeleev arranged the elements by what physical property? boiling poin…
atomic mass
-
what is one way to describe elements? they are the building blocks of m…
They are the building blocks of matter.
-
which correctly links the branch of chemistry with a sample application…
B. Organic chemistry—developing new plastics and materials
-
what happens when aluminum fills its valence shell? three electrons are…
C. Three electrons are lost, creating $\text{Al}^{+3}$
-
a friend tells you knowing science makes it more fun. how would you bes…
Horseplay increases the likelihood of accidents and can damage the equipment.
-
what are groups 1, 2, and 3 examples of on the periodic table? noble ga…
metals
-
select a word from the drop - down menu to correctly complete the state…
Group
-
mike reads the instructions and decides to mix two chemicals before rea…
He should stop and read the entire procedure carefully before continuing the experiment.
-
during an experiment, mike rushes through the instructions and decides …
None of the above options are correct.
-
a friend tells you \playing games during a lab makes it more fun.\ how …
C. Horseplay increases the likelihood of accidents and can disrupt the experiment.
-
how do the atomic mass and atomic number compare for helium? helium doe…
The atomic mass is greater.
-
what would a green color in a benedicts solution mean? no simple sugars…
Small amounts of simple sugars
-
what differs between a radioactive isotope and a stable isotope of the …
Radioactive isotopes last for less time.
-
what does an atomic number represent in an atom? number of protons numb…
number of protons
-
a neutral atom possesses an atomic number of 13 and an atomic mass of 2…
B. outside the nucleus
-
the isotope of an atom containing 40 protons and 51 neutrons suddenly h…
B. Zirconium - 93
-
the isotope of an atom containing 40 protons and 51 neutrons suddenly h…
B. Zirconium - 93
-
hydrogen bonds between water molecules create a force called cohesion. …
Water molecules sticking to each other.
-
multiple - choice question what informational clues can paleoclimatolog…
B. chemical composition of the atmosphere C. precipitation levels
-
directions: answer the questions with the proper information using your…
1. a. Mg b. K c. Fe d. Cu 2. a. Carbon b. Chlorine c. Gold d. Strontium 3. a. 1 b. 4 c. 5 d. 5 4. a. 16 b. 2 c. 17 d. 8 5. Ti 6. Ag 7. Kr 8. 200.59 9. Nickel 10. Cl 11. 11 12. Ti …
-
inscrit le nombre délectrons de valence, le groupe et la période pour c…
8) Bore: 3 électrons de valence, groupe 13, période 2 9) Sodium: 1 électron de valence, groupe 1, période 3 10) Fer: 2 électrons de valence, groupe 8, période 4 11) Brome: 7 élect…
-
given what naomi knows about physical development across the life span,…
1. Carson 2. formal operational
-
in order to prevent bending, sagging, distorting and scratching, what i…
A. in pipe racks
-
when water molecules stick to the walls and other substances it is call…
C. Adhesion
-
38. match each of the following hair textures with its styling tips. a.…
- Chemical services may take longer to process: b. Straight, coarse hair; j. Curly, coarse hair - Remove some interior weight with texture shears: a. Wavy, medium hair; e. Curly, …
-
5 multiple choice 1 point give me an example of a chemical contaminant.…
C. Sanitizer
-
2 true or false 1 point a chef can apply chemicals in his restaurant to…
False
-
which of the following is an example of nonpoint source water pollution…
ocean of trash from an entire world
-
why is thermal pollution a problem? hot chemicals are dumped into ocean…
Hot water from power plants is dumped in lakes which decreases oxygen in the water and kills fish.
-
what is the difference between cohesion and adhesion of water molecules…
Water sticks together in cohesion and to other substances in adhesion.
-
you observe a balloon filled with gas. as the temperature increases, th…
C. Charles' Law
-
which gas law shows the relationship between pressure and volume only? …
C. Boyle's Law
-
only 2 electrons can fit in level 1 only 8 electrons can fit in level 2…
How many protons does your element have? 11 How many neutrons does your element have? 17 What is the charge of your element? 0
-
question 2 (multiple choice worth 4 points) (01.03 mc) emma used an equ…
1.1 g