化学
化学反応、化学量論、分子構造、元素の性質。
-
select the correct answer. dry ice, or solid carbon dioxide, has the mo…
B. compound
-
select the correct answer. which statement is true of a chemical change…
A. It involves changes in the molecular structure.
-
select the correct answer. the ions cr³⁺ and o²⁻ combine to form the io…
D. 2:3
-
select the correct answer. which of these groups of elements show the l…
C. alkali metals (1A)
-
select the correct answer. which is a chemical property of hydrogen? a.…
B. It is a combustible gas.
-
what is the nature of the p - o bond in phosphorus pentoxide (p₂o₅)? el…
B. moderately polar covalent
-
select the correct answer. if the coefficient 2 is placed in front of t…
A. 8 iodine atoms and 18 oxygen atoms
-
which is the correct lewis structure for ethylene, c₂h₄?
A. A
-
select the correct answer. which is the correct lewis dot structure of …
B. H—N—H with a single dot above the N
-
select the correct answer. what is the order in which electrons start f…
A. 1s 2s 2p 3s 3p 4s 3d 4p
-
select the correct answer. the atomic mass of iron is 55.85, and oxygen…
C. 159.7 g
-
14 select the correct answer. using the information in the table, what …
B. 32.060 amu
-
select the correct answer. which types of orbitals are found in the pri…
D. $s, p$
-
select the correct answer. what can you say about a calcium atom by loo…
D. A calcium atom has 20 protons and 24 neutrons.
-
select the correct answer. which of the following states that an orbita…
C. Hund's rule
-
select the correct answer. what causes the difference in bond angles in…
C. the fact that the number of lone pairs of electrons on the central atom is greater in the case of water
-
select the correct answer. the atomic mass of potassium is 39.1. what i…
B. 39.1 g
-
select the correct answer. which pair of atoms has the highest electron…
A. Na - F
-
select the correct answer. which is an example of a solution? a. flour …
C. salt and water
-
select the correct answer. imagine that a new polyatomic anion called \…
B. platonic acid
-
select the correct answer. why does common table salt (nacl) have a hig…
A. It forms an ionic bond with a crystal lattice structure.
-
select the correct answer. methane (ch₄) burns in oxygen to produce car…
B. combustion
-
select the correct answer. using this activity chart, which reaction wi…
B. No reaction occurs.
-
select the correct answer. when an atom in a reactant gains electrons, …
A. Its oxidation number decreases.
-
select the correct answer. give the name and formula of the compound fo…
A. manganese phosphate: $Mn_{3}(PO_{4})_{2}$
-
identifying technologys effect how has technology affected the curiosit…
All of the above (assuming all the listed statements are true in the context of the mission's technological - enabled achievements).
-
which model can be described as negatively - charged electrons orbiting…
The Bohr Model
-
heisenberg proposed the idea that if an electron moves as a wave, it wo…
The Uncertainty Principle
-
which of the following best describes an electron cloud? a collection o…
Electron - containing regions that exist around the nucleus
-
the modern atomic theory shows us that electrons do not travel in defin…
There are regions that exist within an atom where electrons are likely to exist.
-
near the end of the 18th century the first atomic theory was developed.…
Electrons orbit the nucleus in electron clouds
-
complete this quiz to finish the assignment for chemistry - p8 due on s…
Physical; chemical
-
which of the following is not an example of a compound? water limestone…
C. hydrogen
-
in order to find out the empirical formula of a compound such as copper…
La formule empirique est $Cu_{2}O$.
-
instructions: choose an answer and hit next. you will receive your scor…
A compound.
-
a mass spectrometer measures neon to have two masses: 20 and 22 atomic …
A. isotopes
-
which of the following contains the most moles of atoms? answer: a 1 g …
A. 1 g of helium
-
a pharmacist has 80 milliliters of a 25% saline solution. which express…
$y=\frac{0.25(80)+0.1x}{80 + x}\times100$ (corresponding to the fourth option in the original multiple - choice list)
-
which of the following represents a species with 39 protons and 36 elec…
D. $Y^{3+}$
-
determine the molar mass of c₆h₁₂o₆. provide an answer to two decimal p…
180.18 g/mol
-
there are two naturally occurring isotopes of europium, $^{151}\text{eu…
C. 50%
-
how many protons are in an atom of strontium - 90? answer: a 2 b 38 c 8…
B. 38
-
how many protons (p) and electrons (e) are found in a se²⁻ ion? answer:…
A. 34 p, 36 e
-
the net charge on an atom of a given element changes as ____ are added …
C. electrons
-
the net charge on an atom of a given element changes as ____ are added …
D. protons and electrons
-
which particle(s) may be found in the nucleus of an atom? answer: a pro…
B. proton and neutron
-
neutral atoms of all isotopes of a given element have the same ______. …
C. number of electrons
-
how many molecules are in 47.3 moles of co₂? answer: molecules
$2.848406\times 10^{25}$
-
what is the mass in grams of 34.9 moles of nacl?
2039.556
-
determine the quantity in moles of rbf that are in 89.6 grams of rbf.
$0.858$
-
calculate the number of atoms of o in 7.23 moles of fe(no₃)₃.
$3.93\times 10^{25}$ atoms
-
how many neutrons are in a ⁴he atom? answer: a 0 b 2 c 4 d 6
B. 2
-
how many h atoms are in one formula unit of (nh₄)₂so₄?
8
-
which of the following is an example of an empirical formula? incorrect…
C. $C_7H_{14}Cl_2$
-
which of the following is an example of an empirical formula? a c₂h₂o₂ …
D. $C_{6}H_{9}O_{3}$
-
what is the mass number of zinc - 68?
68
-
which of the following species has the same number of electrons as cl⁻?…
A. S²⁻
-
what element with a mass number of 100 has 56 neutrons in its nucleus? …
B. ruthenium (Ru)
-
determine the number of moles in 1.49e23 formula units of cacl₂.
$0.247$
-
how many neutrons are in an atom of uranium - 235? answer: a 92 b 143 c…
B. 143
-
which of the following pairs represent isotopes? a: (^{28}\text{si}) an…
C. \(^{28}Si\) and \(^{29}Si\)
-
when methane is completely combusted in oxygen forming carbon dioxide a…
C. The masses of the reactants and products are equal.
-
what is the mass number for an atom of xenon containing 54 protons and …
131
-
terephthalic acid is a chemical used to make polyesters, including disp…
D. $C_8H_6O_4$
-
what is the atomic symbol and mass number for an atom containing 50 pro…
B. $^{114}\text{Sn}$
-
an unknown element x has the following isotopes: ²⁵x (80.50% abundant, …
$25.41$ amu
-
how many electrons are in a neutral $^{41}$ca atom? answer: a 2 b 20 c …
B. 20
-
determine the molar mass of ag3n. provide an answer to two decimal plac…
337.62 g/mol
-
identify the missing product in the following acid - base reaction. • i…
$Li_{2}CO_{3}$
-
question predict the products of the following acid - base reaction. • …
$H_2O$; $NaCl$
-
question identify the missing product in the following acid - base reac…
$FeF_{2}$
-
balance the following acid - base reaction. • use the simplest possible…
$H_2SO_4 + 2LiOH \longrightarrow 2H_2O+1Li_2SO_4$
-
fill in the blank coefficients in order to balance the following chemic…
1, 1, 1
-
question fill in the blank coefficient in order to balance the followin…
3
-
using the chemical equation provided, identify which of the following a…
- A. Fe - B. O₂
-
using the chemical equation provided, identify which of the following a…
B. 4, C. 3
-
identify the balanced chemical equation. select the correct answer belo…
D. 2 Fe + 3 Cl₂ → 2 FeCl₃
-
question substances that are only present when a chemical reaction is c…
B. products
-
fill in the blank coefficient in order to balance the following chemica…
2, 2
-
the substances generated by the chemical reaction are known as: select …
A. products
-
question 4 what are the negative consequences of organic farming? leach…
D. All of the above
-
6. how many atoms of mercury are in 65.0 grams of it?
$1.95\times 10^{23}$ atoms
-
what is the mass in grams of 3.7 moles ch₄? select the correct answer b…
B. 59 g
-
how many grams of oxygen are there in 2.5 moles of oxygen (o₂) molecule…
C. 80. g
-
5. how many moles are in 9.50 x 10^{25} atoms of copper?
$158$ mol
-
the mass of 1 mole of co₂ is: select the correct answer below: 44 moles…
D. 44 grams
-
4. how many grams are in 4.77 mol of iron?
266.30 g (rounded to two decimal places)
-
compare 1 mole of hydrogen with 1 mole of oxygen. they will have: selec…
The same number of atoms and different masses.
-
how many moles of pcl₅ are present in a 100.0 g sample? select the corr…
C. 0.48
-
for each list, place elements in order of least to greatest electronega…
1) Na, Si, Cl 2) In, Ga, B 3) Na, Si, O
-
3. how many grams of bromine are there in 1.00 x 10^9 bromine atoms?
$1.32\times 10^{-13}$ g
-
type the element in each list with the largest electronegativity: k, fr…
Li Cl F N
-
2. how many atoms are in 6.85 mol of neon?
$4.13\times 10^{24}$ atoms
-
a ______ is defined as the amount of substance containing the same numb…
B. mole
-
for each list, place elements in order of least to greatest ionization …
1) Li, O, N 2) Ra, Ba, Si 3) Pb, Sn, C
-
1. how many moles are in 9.20 g of nitrogen?
0.657 mol
-
type the element in each list with the largest ionization energy: te, p…
Se Te F Cl
-
abbreviated atomic notation # of protons # of neutrons # of electrons f…
| Abbreviated Atomic Notation | # of Protons | # of Neutrons | # of Electrons | |---|---|---|---| | F - 37 | 9 | 28 | 9 | | | 38 | 48 | 38 | | Co - 55 | 27 | 28 | 27 |
-
for each list, place elements in order of least to greatest atomic radi…
1) Ar, Si, Na 2) B, Ga, In 3) Ne, Br, Cs
-
complete atomic notation, # of protons, # of neutrons, # of electrons 3…
| Complete Atomic Notation | # of Protons | # of Neutrons | # of Electrons | |---|---|---|---| | $_{34}^{65}Se^{2 -}$ | 34 | 31 | 36 | | $_{13}^{28}Al^{3+}$ | 13 | 15 | 10 | | $_{…