化學
化學反應、化學計量、分子結構與元素性質。
-
4. classify the following compounds as ionic or molecular: a) mgcl₂ b) …
4. a) Ionic b) Ionic c) Molecular d) Molecular e) Ionic 5. a) Cesium bromide b) Barium oxide c) Calcium phosphide d) $KCl$ e) $AlBr_3$ f) $K_2O$ 6. a) Diphosphorus pentoxide b) Ca…
-
think it over 4. apply study the oxygen atom illustrated below. is the …
No, the second energy level of the oxygen atom is not full. The second energy level can hold a maximum of 8 electrons, but the oxygen atom has only 6 electrons in its second energ…
-
key concept summary • chemical compounds are formed from elements in th…
2a. Iron, Fe 2b. Group 17 (halogens), because they need one electron to complete their outer shell. 2c. Cesium (or Francium), because it has a large atomic radius and easily loses…
-
step 1 look at the formula of the molecular compound: co₂. use the peri…
carbon dioxide
-
take a look 3. draw conclusions table salt is a compound made of sodium…
No, you cannot separate sodium from chlorine by crushing salt crystals because crushing is a physical change and does not break the chemical bonds in the sodium - chloride compoun…
-
an increase in temperature will cause an increase in diffusion rate bec…
the frequency and force of molecular collisions increases.
-
what do these two changes have in common? mixing chocolate syrup into m…
Both are only physical changes.
-
what do these two changes have in common? sanding a piece of wood dew a…
Both are only physical changes. Both conserve mass.
-
the mass of 75,000 molecules of oxygen is grams. (use scientific notati…
$3.975\times 10^{-18}$ grams
-
which dye would you predict to move the fastest (and thus go furthest i…
potassium permanganate (mw = 158 g/mol)
-
as molecular weight increases, multiple choice the rate of diffusion re…
the rate of diffusion decreases.
-
what do these two changes have in common? boiling an egg ice crystals f…
A. Both conserve mass.
-
what do these two changes have in common? knitting yarn into a scarf yo…
Both are only physical changes.
-
what do these two changes have in common? firing a clay pot in a hot ki…
Both conserve mass., Both are chemical changes.
-
what do these two changes have in common? using polish to remove tarnis…
C. Both conserve mass., D. Both are only physical changes.
-
1st attempt part 1 (1 point) give the name for the fourth (missing) oxo…
Part 1: Perchloric acid Part 2: $HClO_4$
-
what do these two changes have in common? using polish to remove tarnis…
Both conserve mass., Both are only physical changes.
-
get it? 2. identify three pieces of information about an element you ca…
Atomic number, Element symbol, Atomic mass
-
1. why did the volume of the gas molecules increased in the balloon aft…
The gas particles inside the balloon were more densely packed together in the model of air in the balloon before it is warmed up by the heating pad. We know this because when a ga…
-
drag the words/phrases to complete the sentences. alkali metals are hig…
reactive, lose 1 electron
-
arrange the following elements, from top to bottom, in the correct orde…
Te, Sb, In, Sr, Rb
-
arrange the following atoms, top to bottom, in the correct order of inc…
Cs, Rb, K, Na, Li
-
with the exception of he, how many valence electrons do noble gases hav…
D. 8
-
which characteristic is not a periodic trend? a. atomic radius b. ioniz…
C. Number of elements in a group
-
which of the following is classified as a compound? * silicon dioxide h…
C. water
-
review progress question 8 of 15 the noble gas is most likely element c…
1: Element 1
-
review progress use the figure to answer questions 10 and 11. first 3 e…
A. Ar, B. Cl, D. O
-
name: ervin lopez assignment: percent error, density, & kmt 1 a student…
1. 5.58% (closest to option D in problem 1) 2. 10% (option 4 in problem 2) 3. 3. nitrogen (option 3 in problem 3) 4. 4. Ni (option 4 in problem 4) 5. 4. The volume of the gas part…
-
use the figure to enter the correct symbol for the elements. an element…
1. S 2. Al³⁺, Mg²⁺ 3. O
-
the united nations declared the year 2019 as the year of the periodic t…
A. It is relatively unreactive. C. It has a full valence shell of electrons.
-
study the following sketch of a molecular orbital (mo) in a homonuclear…
Write the symbol for this MO: $\pi$ Is this a bonding or antibonding MO? bonding What is the energy of this MO, compared to the energy of a 3p orbital on one of the separate atoms…
-
the united nations declared the year 2019 as the year of the periodic t…
A. Nh
-
the united nations declared the year 2019 as the year of the periodic t…
A. have 7 shells of electrons
-
the united nations declared the year 2019 as the year of the periodic t…
D. It would most likely form cations when it reacts.
-
a lab experiment begins with 500 milliliters of a chemical solution. th…
A. 330 milliliters
-
an environmental scientist is investigating the volatility of 175 organ…
105
-
multiple choice 15 points what holds metallic bonds together? the oppos…
Free flowing electrons in between the atoms
-
look at this sentence: if you want to work in this chemistry lab, you m…
3. to act in agreement with: Please listen carefully and follow the directions.
-
fill in the blank 15 points a metal is a answer consisting of closely -…
1. solid 2. valence 3. not 4. nonlocalized 5. positive 6. electrical
-
multiple choice 15 points what is an alloy? solid homogeneous mixture f…
Solid homogeneous mixture formed by dissolving one solid in another solid
-
multiple answer 15 points select all of the following that applies to m…
B. Sea of Electrons, C. Delocalized Electrons
-
true or false 5 points metals form covalent bonds with other metals. tr…
False
-
multiple answer 15 points. which of the following are properties of met…
They lose electrons to become Cations They have luster Good conductors of heat and electricity High melting and boiling points They are malleable and ductile Low ionization energy…
-
notes quiz and practice - metallic bonding 1 multiple choice 5 points m…
B. cations
-
look at this sentence: if you want to work in this chemistry lab, you m…
3. to act in agreement with: Please listen carefully and follow the directions.
-
name kimberly lemos p5 date clay math crossword puzzle: chemistry acros…
Across: 1. Electron 5. Reaction 6. Plasma 9. Neutron 11. Noble 13. Mass 14. Carbon Down: 2. Two 3. Proton 4. Hydrogen 6. Periodic 7. Metal 8. Nucleus 10. Number 12. Ion
-
23. complete the table. | | atomic size | ionization energy | electrone…
| | Atomic Size | Ionization Energy | Electronegativity | |--|--|--|--| | Definition | The distance from the nucleus to the out - most electron shell of an atom | The energy requi…
-
nitrogen what is the atomic number? what is the mass number? what is th…
\(1s^{2}2s^{2}2p^{3}\)
-
2.3 bohr models name: directions: draw bohr models for each element lis…
# Explanation: ## Step1: Recall atomic number for protons The atomic number of an element is equal to the number of protons. Sodium (Na) has an atomic number of 11, so the number …
-
24. complete the table about element properties. | | metals | nonmetals…
| | Metals | Nonmetals | Metalloids | |--|--|--|--| | Properties | 1. Good conductors of heat and electricity <br> 2. Have a luster <br> 3. Malleable and ductile | 1. Poor conduct…
-
2.3 bohr models directions: identify the bohr models.
Top - left: Silicon (Si); Top - right: Fluorine (F); Bottom - left: Calcium (Ca); Bottom - right: Boron (B)
-
24. complete the table about element properties. | | metals | nonmetals…
| | Metals | Nonmetals | Metalloids | |--|--|--|--| | Properties | 1. Good conductors of heat and electricity <br> 2. Malleable <br> 3. Ductile | 1. Poor conductors of heat and el…
-
what happens when sodium undergoes a chemical reaction with chlorine? t…
1. A new compound is formed called salt. 2. Toxic 3. A change on the molecular level
-
what can you infer about the changes that formed the grand canyon? they…
1. C. They were physical changes. 2. B. Through a chemical reaction between iron and oxygen
-
a chemist combines water and isopropanol to make a mixture with a volum…
28
-
he called all his people together and told them his daring scheme. sour…
A. plan
-
the police union regards the move as an insult that ______ officers cou…
D. implies
-
13 multiple choice 1 point what does it mean when there is a physical c…
13. Matter has changed size, shape or form. 14. Food being broken down by enzymes in your stomach 15. Food being broken into small pieces by your teeth
-
11 multiple choice 1 point which of the following is an example of a ph…
1. Water freezing into ice 2. A chemical change
-
dry ice has the same chemical properties as what gas? helium hydrogen n…
1. D. Carbon Dioxide 2. B. They bounce around randomly.
-
6 multiple choice 1 point the melting point of h₂o is 0 degrees celsius…
6. D. Freezing point 7. A. Sublimation
-
what do water vapor, liquid water, and ice have in common? the same cry…
1. D. The same chemical properties 2. A. Heating it
-
what are the three main states of matter? solid, liquid, and gas ice, w…
1. Solid, Liquid, and Gas 2. They move more freely 3. Matter is anything that has mass and takes up space
-
after mixing two substances together, a cloudy layer forms and powder b…
1. Chemical change 2. Physical change 3. Chemical change
-
multiple answer 1 point you are baking bread in your oven. which two se…
A. sight D. smell
-
why is a change in temperature evidence that a chemical change has take…
1. Energy is released as a new substance is created 2. a chemical change
-
why is dissolving sugar into water a physical change? they form a compo…
1. They can be separated physically 2. the chemical reaction between the two substances
-
1 multiple choice 1 point why is water turning to a gas a physical chan…
1. It is still $H_2O$ 2. $H_2O$ gas
-
when scientists think a chemical might be risky, what rule says we need…
Precautionary Principle
-
read the final stanza. identify the rhyme scheme by using the drop - do…
Though I am old with wandering: A Through hollow lands and hilly lands: E I will find out where she has gone: F And kiss her lips and take her hands: E And walk among long dappled…
-
what is an example of a fortified food? o natural supplements o iodized…
Iodized salt
-
question 16 which of the following is the best practice when handling c…
1. Store them in a designated area away from food
-
5. explain how gasoline powers an engine? 6. how much air is needed to …
5. Gasoline is ignited in cylinders, combustion pushes pistons converting chemical to mechanical energy. 6. About 14.7 pounds of air for stoichiometric combustion. 7. Carbon dioxi…
-
changes to state of matter or phase of matter are what type of change? …
Physical change
-
which type of change has occurred if you can reverse the substance back…
A. Physical change
-
why does the video say that burning something is a chemical change? bec…
because it cannot be changed back to the original form
-
is tearing a piece of paper a chemical or physical change? chemical cha…
B. physical change
-
what did the vinegar do to the pennies? made them feel rough made them …
made them shiny
-
why do you think vinegar is used in so many experiments for chemical ch…
It is a highly reactive acid.
-
since the soap is hydrophobic (afraid of water), it sticks to which kin…
B. fat molecules in milk
-
why does the bottle explode? the gas produced from the reaction causes …
The gas produced from the reaction causes the pressure.
-
what type of property is dependent on how something reacts with somethi…
B. Chemical Property
-
write a p for physical and a c for chemical next to each property below…
11. P 12. P 13. C 14. P 15. C
-
1 multiple choice 1 point which one describes a chemical change? someth…
a new substance is made
-
the fentanyl crisis is a complex and urgent issue. here are some key qu…
1. Es un analgésico sintético muy potente. 2. Su alta potencia puede causar sobredosis y muerte. 3. Actúa sobre el sistema nervioso central, con efectos como sedación y depresión …
-
7. use the triangle to the left to determine the following: what is the…
$20\ g$
-
part 1c: describe a feedback loop involving permafrost thaw that includ…
- What is the rate of the chemical reaction between soil carbon and air oxygen? - How much extra carbon dioxide will be generated compared to the initial model? - How will the add…
-
temperature plays a role in both physical and chemical changes by influ…
particle energy and movement
-
what are some observations that indicate a chemical change? gas formati…
D. All of these options indicate a chemical change
-
13/16 what is a chemical change? a change that can be easily reversed b…
A change that involves the formation of new substances with different properties
-
match the arrangement to the state of matter
First arrangement - Solid Second arrangement - Gas Third arrangement - Liquid
-
which of the following is a change from solid to gas? d) freezing a) me…
B. Sublimation
-
what is the phase change from liquid to solid called? freezing melting …
Freezing
-
what is a physical change? a change in which the substance retains its …
A. A change in which the substance retains its original properties
-
fill in the blank: the process of changing from gas to liquid is known …
condensation
-
which of the following is an example of a chemical change? burning wood…
A. Burning wood
-
independent practice: write equations in multiple variables practice* m…
$5a + 7b+9c = 300$
-
period chemistry worksheet name 1. give the chemical symbol for each of…
1. a. Br; c. Hg; e. F; h. Bi 2. a. Ag; c. Cd; e. Sn; h. Al; d. Sb; f. As 3. a. 2; b. 2; c. 2; d. 3; e. 1; f. 3 4. With OH⁻: Fe(OH)₂, Al(OH)₃, Hg(OH)₂, NH₄OH, NaOH With Cl⁻: FeCl₂,…
-
which process represents a chemical change?* 1 point boiling water cutt…
Frying an egg
-
what is a key indicator that a chemical change has occurred? * a change…
A change in temperature, color, or a gas forming