化學
化學反應、化學計量、分子結構與元素性質。
-
what is the percent composition of hydrogen in a compound if the mass o…
C. 15.0%
-
select the correct answer. the mineral benitoite is a gemstone for maki…
A. $BaTiSi_{3}O_{9}$
-
question 16 (2 points) a combination of two or more atoms joined by a b…
B. a molecule
-
this type of shape is composed of unpredictable, irregular lines? selec…
C. organic
-
question 13 (2 points) listen which of these represents the correct ord…
D. hydrogen, ionic, covalent
-
question 24 (2 points) listen muscles are designed to provide what func…
motion and support of our moveable skeleton
-
closure: on a piece of paper, draw two demand curves (two different gra…
The demand curve for chemotherapy will be more inelastic (steeper) compared to the demand curve for cookies. When drawing the two demand curves on a graph with price (P) on the ve…
-
in a two - dimensional work, when the figure becomes the background and…
D. a figure - ground reversal
-
directions: choose the term that best completes the second relationship…
1. Science; Scientific method 2. c. Physicians 3. D. Organic
-
a shape on a flat picture surface that is defined by surrounding empty …
A. an implied
-
look for chlorine with symbol cl and atomic number 17. is it a metal, n…
Nonmetal
-
look at francium with symbol fr and atomic number 87. what is its group…
Group 1 Period 7
-
3 li lithium 6.941 how many neutrons does the element lithium have? 6.9…
C. 4
-
how many neutrons does the element polonium have? polonium 84 po 209 hi…
125
-
how many protons does the element xenon have? 77 54 131 131.29
B. 54
-
identify the type of organic compound shown below: ch3 - c = o | o | ch3
Ester
-
a physical reaction is_____. a change that does not make something new …
1. a change that DOES NOT MAKE SOMETHING NEW and different from the starting substances 2. 54
-
what element is represented by the following bohr model? aluminum hydro…
C. Magnesium
-
what element is represented by the following bohr model? o potassium o …
Chlorine
-
the compound shown here is what type of organic compound?
Aromatic compound
-
identify the following question as a physical or chemical change you co…
Chemical Change
-
adapted from presidential retreat by the national parks service camp da…
a piece of relevant supporting evidence
-
when water boils (liquid to a gas)and becomes steam that is called? mel…
B. Evaporation
-
reading check 1. which of the following is a subatomic particle? a. car…
1. c. Electron 2. a. Protons, c. Neutrons 3. d. An atom of oxygen has 8 protons. 4. a. Molecules are made of several atoms bonded together.
-
identify the best iupac name for the compound having the condensed form…
4-ethyl-1,1,1-trimethylhexane
-
the reactants are. choose one option. a the substances present when the…
The question seems incomplete as it doesn't clearly state what needs to be done with the options (e.g., which one is correct). However, based on the content, the discipline is Nat…
-
the tiny particles that make up matter are called atoms. true false que…
- First question: True - Question 6: D. carbon - Question 7: True
-
from the periodic table, it can be determined that iron (fe) has an ato…
107 amu
-
which of the following molecules shows two atoms of hydrogen (h)? (1 po…
$H_2SO_4$
-
what does the law of conservation of mass say about a chemical reaction…
In a chemical reaction, mass is neither created nor destroyed.
-
match the correct word with its definition. element choose matter choos…
Element: Pure substance made up of only one kind of atom Matter: Has mass and takes up space Atomic Weight: The number of neutrons and protons in an element Atomic Number: The num…
-
what are the reactants in a chemical formula? (1 point) the atoms left …
the atoms prior to the chemical reaction, found on the left side of the equation
-
question 1 - 2 hydrogen bonding is responsible for unique properties of…
C. A hydrogen bond forms between the oxygen atom of one water molecule and the oxygen atom of a different water molecule
-
presidential retreat adapted from the national park service catoctin mo…
1. The park was originally used for several different camps, including a family camp for federal employees. 2. President Franklin D. Roosevelt needed a summer retreat, to escape D…
-
the graduated cylinder below shows major scale divisions every 5 ml. ho…
37.0 mL
-
which change is likely to happen to an atom of the element strontium (s…
It will give up electrons, forming a positive ion.
-
how many valence electrons are in an atom of the element fluorine? (1 p…
C. seven
-
why do atoms exchange or share electrons during bonding? (1 point) to b…
to obtain a full outer electron shell
-
question 1 - 2 hydrogen bonding is responsible for unique properties of…
C. Un enlace de hidrógeno se forma entre el átomo de oxígeno de una molécula de agua y un átomo de hidrógeno de una molécula de agua diferente.
-
what are valence electrons? (1 point) electrons that are exchanged betw…
the electrons in an atom's outermost energy level
-
development of acids and bases, glassware, and better techniques for me…
A. TRUE
-
which feature defines a neutral atom? (1 point) ○ a full outer electron…
the number of electrons equal to the number of protons
-
the alchemists eventually succeeded in turning base metals into gold. t…
FALSE
-
hydrogen bonding is responsible for unique properties of water. which c…
C. A hydrogen bond forms between the oxygen atom of one water molecule and a hydrogen atom of a different water molecule.
-
question 1-2 hydrogen bonding is responsible for unique properties of w…
C. A hydrogen bond forms between the oxygen atom of one water molecule and a hydrogen atom of a different water molecule.
-
which of the following is not a contribution that alchemists made to th…
d. discovered subatomic particles
-
what were the three major streams of alchemy that are known? a chinese,…
A. Chinese, Indian, and European
-
modern scientists can change lead into gold by nuclear bombardment. wha…
b. It is too expensive.
-
b/ identify the equipment show a) test tube b) ring clamp c)mortar d) t…
1st drawing: l) beaker 2nd drawing: m) rubber stopper (cork) 3rd drawing: d) test tube tongs 4th drawing: c) mortar 5th drawing: e) graduated cylinder 6th drawing: k) erlenmeyer f…
-
one goal of the alchemists was to find a way to turn base metals into g…
A. silver
-
in what way(s) did alchemists contribute to modern chemistry? select al…
A. organizing and classifying substances to predict the products of reactions D. producing gunpowder, glass, and ceramics
-
module 1 exam chemistry part 1 ae teacher (acc ed) / module 1: chemistr…
Quantitative data is numerical and measurable, while qualitative data is descriptive and non - numerical.
-
19. what is the difference between organic chemistry and inorganic chem…
Organic chemistry is the study of carbon - containing compounds, while inorganic chemistry focuses on non - carbon compounds.
-
name: j - lovem(?) date: 2. sam was mixing a solution of salt and water…
1. Rinse eyes with water for 15 - 20 minutes, then seek medical help. 2. Rinse hand with water, apply neutralizing agent if available, seek medical advice if needed.
-
9. if an element has 7 electrons, what is the element name? 10. an endo…
9. Nitrogen 10. Absorbs 11. Releases 12. Direct 13. A gas expanding in a cylinder and doing work while absorbing heat 14. a. +
-
9. explain the difference between accuracy and precision.
Accuracy is closeness to true value; precision is closeness of repeated measurements to each other.
-
3. how do you know if an element is an isotope?
If atoms of an element have the same atomic number but different mass - numbers (owing to different numbers of neutrons), they are isotopes.
-
question 1 - imagine you have a bottle of vinegar and water used to cle…
Yes, changing the amount of water affects how acidic it is. Adding more water makes the solution less acidic because it dilutes the concentration of the acid (acetic - acid in vin…
-
which of the following is an organic molecule? a. nacl b. feo c. ch₄ d.…
C. CH₄
-
mg 24.305 atomic # = atomic mass = # of protons = # of neutrons = # of …
| Element | Atomic Number | Atomic Mass | # of Protons | # of Neutrons | # of Electrons | | ---- | ---- | ---- | ---- | ---- | ---- | | Mg | 12 | 24.305 | 12 | 12 | 12 | | Ar | 18…
-
which of the diagrams best shows the arrangement of molecules in a liqu…
C. (suponiendo que la opción C muestra moléculas desordenadas y relativamente cerca una de otra dentro del recipiente)
-
question 20 of 25 what is in the cloud of negatively charged particles …
D. Electrons
-
question 19 of 25 look at the word equation below. glucose + fructose →…
A. Dehydration of simple sugars
-
16 s 32.06 atomic # = __ atomic mass = __ # of protons = __ # of neutro…
| Element | Atomic Number | Atomic Mass | # of Protons | # of Neutrons | # of Electrons | | ---- | ---- | ---- | ---- | ---- | ---- | | S | 16 | 32.06 | 16 | 16 | 16 | | I | 53 | …
-
question 18 of 25 what happens when a sodium atom loses an electron in …
B. It becomes a positive ion.
-
what type of energy is food? a. thermal b. sound c. chemical d. mechani…
# Breve explicación: La comida contiene compuestos químicos como carbohidratos, proteínas y grasas. Estas moléculas químicas almacenan energía en sus enlaces químicos. Cuando el c…
-
question 16 of 25 which molecule most likely has the greatest amount of…
B. O=C=O
-
question 14 of 20 which best describes the nucleus of an atom? a. it is…
D. It is the part of the atom with the greatest mass.
-
o 15.999 atomic # = ____ atomic mass = ____ # of protons = ____ # of ne…
**Oxygen**: Atomic number = 8 Atomic mass = 15.999 Number of protons = 8 Number of neutrons = 8 Number of electrons = 8 **Zinc**: Atomic number = 30 Atomic mass = 65.38 Number of …
-
what type of energy creates lightning? a. electrical b. mechanical c. s…
# Breve explicación: La relámpago es un fenómeno eléctrico causado por la descarga de electricidad entre nubes o entre una nube y la tierra. La energía eléctrica es la responsable…
-
which atoms form an ionic bond? a. magnesium and lithium b. magnesium a…
B. Magnesium and bromine
-
select the correct compound. reactants undergo chemical reaction to for…
The coefficient of $O_2$ (which is 10 in the given equation instead of 13) is incorrect.
-
88 multiple choice listen what does earth science primarily study? a di…
A. different processes and systems of Earth
-
mass is considered a ______ property extensive intensive
Extensive
-
what does the --> sign mean in this equation: h2o --> h2 + o2 enzyme ac…
yield
-
bohr model drawing (25 points) draw a bohr - model of an oxygen atom in…
In the Bohr - model drawing of an oxygen atom: - Nucleus contains 8 protons and 8 neutrons. - First electron - orbit (closest to the nucleus) has 2 electrons. - Second electron - …
-
gloves are made from a synthetic rubber and provide protection from a v…
B. Neoprene
-
13) a ph is a logarithmic scale that is used to describe the relative c…
False ### 14
-
h2 is an molecule mixture element compound
Molecule
-
8) acid has the same ph as... (a) acidic (b) neutral (c) ph (d) basic 9…
1. A. acidic 2. D. 14 3. D. neutralization 4. D. baking soda with a pH value of 8 - 9
-
a feature of organic compounds not found in inorganic compounds is the …
C. carbon atoms covalently bonded to each other
-
example 3.6: constant - pressure calorimetry ammonium nitrate (nh₄no₃, …
$q = 6.12\times10^{3}\ J$ (the magnitude of the heat absorbed by the dissolving process), and the process is endothermic.
-
3) acids have a ph value ____ than 7. 4) bases have a ph value ____ tha…
3. lower 4. higher 5. The concentration of hydrogen ions ($H^+$) in a solution. 6. True 7. B. 7
-
15 mark for review in a chemical reaction a chemical bonds can be forme…
D. All answers are correct
-
oil and water are a ______ mixture. homogenous heterogenous
B. Heterogenous
-
1) according to the image above, which substance has the strongest acid…
1) The substance with the lowest pH value shown in the image is the strongest acid. 2) The substance with the highest pH value shown in the image is the strongest base.
-
24) place these unknown ph test papers in order from most acidic to mos…
24) Need to see the actual colors on the pH - test papers compared to the chart to determine the order. 25) B. 4
-
21) name the acid or base for label d. 22) identify all the substances …
21) Cannot be determined 22) A. tomatoes (pH = 4), B. cola drinks (pH = 3), D. vinegar (pH = 5.6) 23) B. detergent (pH = 10), C. baking soda (pH = 8), D. oven cleaner (pH = 14)
-
18) name the acid or base for label a. 19) name the acid or base for la…
A) tomatoes (pH = 4) B) cola drinks (pH = 3) D) vinegar (pH = 5.6)
-
13) a substance that conducts electricity when dissolved in water are c…
13. C. electrolytes 14. True 15. B. water, D. salt 16. D. a substance that when dissolved in water produces OH - ions, it is an OH - donor 17. B. a substance that when dissolved i…
-
11) in terms of ph, explain what would happen if you mixed vinegar with…
11. D. the pH level of the solution would be between 3 and 11 12. B. The lemon has a lower pH than the apple.
-
7) the ph of a strong base would be closest to oa) 0 ob) 7 oc) 14 8) th…
7. C. 14 8. A. 0 9. A. acid 10. D. acid and base
-
bohr model drawing (25 points) draw a bohr model of an oxygen atom in t…
Protons: 8 Neutrons: 8 Electrons: 8 (For the drawing: Draw a nucleus in the center. Label it with 8 protons and 8 neutrons. Draw two electron - orbits around the nucleus. Place 2 …
-
3) identify all the properties of an acid. a) bitter taste b) corrosive…
3. B. corrosive, C. pH level less than 7, D. sour taste 4. B. bitter taste, E. pH value greater than 7 5. B. use pH paper or litmus paper 6. B. lemon juice is an acid
-
part b. 1.draw the bohr - rutherford model of atomic structure for elem…
(1) For Beryllium (Be, atomic number = 4) in Bohr - Rutherford model: Draw a nucleus with 4 protons and 5 neutrons (approximate number of neutrons for most common isotope). Then d…
-
label the parts of an atom on the diagram below. 4. what type of charge…
4. Positive charge 5. Neutral charge 6. Negative charge 7. Protons and neutrons 8. 35 9. 6 (assuming 6 protons in the diagram) 10. 12 (assuming 6 protons and 6 neutrons in the dia…
-
41) what is the difference between dilution and concentration? 42) iden…
41) Dilution reduces solute - to - solvent ratio by adding solvent; concentration is amount of solute in solution. 42) B. dilute solution 43) A. concentrated solution 44) A. conce…
-
36) what is solubility? oa) the ability of a given substance(solute) to…
36) A. The ability of a given substance(solute) to dissolve into a solvent. 37) False 38) C. Polar solvent molecules separate the molecules of other polar substances. 39) B. What …
-
32) reactions that can not occur spontaneously are.. oa) exothermic ob)…
32) B. endothermic 33) B. endothermic 34) A. exothermic 35) B. endothermic
-
how did chemistry start? by accident as experimentation an apple fallin…
Alchemy and philosophy