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Friday, July 3, 2020
THAY LỜI KẾT (THƠ VÀ ĐÁ)
Wednesday, July 1, 2020
Chemistry UNIT 1 - Practice Assessment
1. Which branch of chemistry is concerned with the detection or identification of substances present in a sample and their amount?
2. Identify the INCORRECT statement below:
3. Which of the following properties of Na metal is a physical property?
4. Which of the following property is NOT an intensive property of a material?
5. Which of the following materials has NOT been properly classified?
6. The correct symbol for the element Tin is:
7. The most abundant element by % mass in the Earth¹s crust, oceans and atmosphere is:
8. Which is an INCORRECT statement regarding the SI system of units?
9. The density of Fe is 7.86 g/mL. Convert this to pounds per cubic foot.
10. This summer I took a 4500 mile vacation in a van which gets 13 miles/gallon of gasoline. If the average price of gasoline on the trip was $1.27 per gallon, how many dollars did I spend on gasoline?
11. A reaction requires 10.0 g ethanol. What volume of ethanol/water mixture which is 60% ethanol by mass would be required? The Specific Gravity of this mixture is 0.8937.
12. Permalloy steel is an alloy which is 21.2% Fe by mass. How many grams of Fe are present in 1.000 kg of steel?
13. Which distance is greater? (Given: 1 Ångstroms = 1 x 10-10 m)
KEY
1)a 2)c 3)b 4e 5)d 6)a 7)b 8)a 9)b 10)e 11)d 12)a 13)b1. Identify the INCORRECT statement below:
2. Which is an INCORRECT statement regarding unit systems?
3. Which element is INCORRECTLY matched with its symbol?
4. Which of the following property is an intensive property of a material?
5. Which of the following properties of water is chemical property?
6. Which element below is NOT among the five most abundant elements by % mass in the Earth's crust, oceans and atmosphere?
7. Denatured alcohol is ethyl alcohol to which various agents have been added to render it unfit for human consumption. A particular formula of denatured alcohol has 91% ethyl alcohol by mass. How many grams of ethyl alcohol are present in 500 g of this denatured alcohol?
8. Which of the following materials has NOT been properly classified?
9. The density of Au is 19.3 g/mL. What would be the value of a 100 cm3 ingot of gold if gold is worth $35 per ounce. (Note: There are 16 ounces in a pound; 1 pound = 0.4536 kg)
10. Which volume is greater? (Given: 1.00 in = 2.54 cm)
11. I want to measure out 50 grams of liquid methanol from a bottle on the shelf. The density of liquid methanol is 0.79 g/mL. How many mL do I need to measure out?
12. Which branch of chemistry is concerned with, among other things, the energy changes associated with chemical reactions?
KEY
1)c 2)a 3)e 4)c 5)b 6)d 7)b 8)a 9)c 10)b 11)e 12)d1. Which state of matter does not completely fill its container and has no definite shape of its own?
2. Which state of matter is most easily compressed?
3. Which of the following substance classifications is NOT CORRECT?
4. A motorcycle engine has a displacement volume of 650 cubic centimeters (650 cm3). What is the volume in cubic inches?
5. An ore is mined in which the cobalt content is 1.2% by mass. How many pounds of ore must be processed to yield 15 pounds of cobalt?
6. An iodine atom has a diameter of 2.66 x 10-10 m. If iodine atoms are lined up so that they are just touching, how many of them would it take to have a line 1.00 feet long?
7. Which of the following is a chemical change involving silver?
8. Below are five properties concerning a sample of elemental gallium. Which of the following answers specifies all the intensive properties?
9. Which of the following is an example of a compound?
10. The element indium has a density of 7.31 g/cm3. What is the mass of a piece of indium whose volume is 0.52 cm3?
11. In order to achieve orbit, a rocket has to reach a speed of 5.0 mile/second. What is this speed in kilometers/hour? (1 mile = 5280 feet, 12 in = 1 foot, 1 meter = 100 centimeters, 1 kilometer = 1000 meters)
12. Which of the following element/symbol combinations is NOT CORRECT?
KEY
1)b 2)a 3)a 4)b 5)a 6)c 7)b 8)d 9) b 10)a 11)b 12)d1. The EPA emission standards limit each automobile exaust to 23.0 g of carbon monoxide (CO) per mile. In an average city there are 82,700 cars, each driven an average 13.5 miles/day. How much CO (in kg) can be legally discharged into the atmosphere each day?
2. Of the following properties of sucrose, which ones are chemical properties?
3. Which branch of chemistry deals with determining the identity and composition of matter?
4. Which of the following processes are exothermic?
5. Which of the following properties would not be useful in charecterizing a substance?
6) Which of the following statements is FALSE?
7. Which of the following materials is NOT a pure substance?
8. In Biblical times, volume was measured by the OMER and weight by the SHEKEL. Given the conversions below, calculate the density of gasoline (0.680 g/mL) in sheckels/omer.
9. Nichrome is an alloy (mixture) commonly used to make heating elements. It is composed of 60% nickel, 24% iron and 16% chronium. If you have 2.15 g of nichrome wire, how much of each element do you have?
10. The same amount of heat is added to a 25 g sample of each of the metals below. If they are all initially at 25oC, which will reach the highest temperature?
11. The density of octane is 0.702 g/mL. What is the volume of 63.0 g of octane?
12. The statement that the total mass does not change in a chemical reaction is the Law of:
13. From the decomposition of an unknown solid, one obtains a gas and a new solid, both of which are pure substances. From just this information it can be said, without a doubt, that:
14. Which of the following properties do liquids and gases have in common?
15. The fact that compound calcium carbonate is made up of 40% calcium, 12% carbon, and 48% oxygen is an illustration of the Law of:
KEY
1)c 2)c 3)a 4)d 5)b 6)e 7)e 8)d 9)c 10)e 11)b 12)a 13)d 14)b 15)aPhạm Công Thiện: TRÁCH NHIỆM CỦA TUỔI TRẺ VIỆT NAM VỚI QUÁCH TẤN
Scientific Notation and Significant Figures Worksheet 3
Scientific Notation/Significant Figures Worksheet 3 |
a) 10.0005 g ______
b) 0.003423 mm ______
c) 2900 + 100 ft ______
d) 8.9 x 105 L ______
e) the number of minutes (60) that make up an hour ______
2. Determine the answer for each of the following. Be sure to use the correct number of significant figures.
a) 27.34 b) 2.8023
6.90 - 4.762
+ 13.124
c) 0.32 x 14.50 x 120 = d) 24.1 / 0.005 =
3. Round each of the following to 3 significant figures.
707.5 ____________ 2,300.2 ______________
0.0003350 _____________ 10.26730 _______________
18.95 x 1021 ______________
4. Convert each of the following into correct scientific notation.
1747 _________________________________
0.00000984 ___________________________
3200.0 x 102 ____________________________
0.002014 x 102 __________________________
25600000000000000 ______________________ (use 4 sig. fig. for the last one only)
5. Calculate the following using the correct number of significant figures.
a) 2.34 x 1047 b) 9132.0
+ 9.2 x 1046 - 1.6 x 103
6. Calculate the following using the correct number of significant figures.
a) (1.54 x 1058)(3.5 x 1060)
b) (7.9 x 1034) / (8.32 x 1023)
Answers - Worksheet 3 |
a) 10.0005 g 6
b) 0.003423 mm 4
c) 2900 + 100 ft 2
d) 8.9 x 105 L 2
e) the number of minutes (60) that make up an hour infinite
2. Determine the answer for each of the following. Be sure to use the correct number of significant figures.
a) 47.36 b) -1.960
c) 5.6 x 102 d) 5 x 103
3. Round each of the following to 3 significant figures.
708 2.30 x 103
0.000335 10.3
19.0 x 1021
4. Convert each of the following into correct scientific notation.
1.747 x 103
9.84 x 10-6
3.2000 x 105
2.014 x 10-1
2.560 x 1016
5. Calculate the following using the correct number of significant figures.
a) 3.26 x 1047 b) 7.5 x 103
6. Calculate the following using the correct number of significant figures.
a) 5.4 x 10118
b) 9.5 x 1010
Scientific Notation and Significant Figures Worksheet 2
Scientific Notation/Significant Figures Worksheet 2 |
1. Convert each of the following into scientific notation.
727 _________________________________
172000 _________________________________
0.000984 _________________________________
200.0 x 102 _________________________________
0.014 x 102 _________________________________
2560000000000000000000000000000000 __________________________
(use 4 sig. fig. for the last one)
2. Convert each into decimal form.
1.56 x 104 _________________________________
3.6 x 10-2 _________________________________
736.9 x 105 _________________________________
0.0059 x 105 _________________________________
0.00059 x 10-1 _________________________________
3. Calculate the following. Give the answer in correct scientific notation.
a) 2.34 x 1065 b) 313.0
+ 9.2 x 1066 - 1.2 x 103
4. Calculate the following. Give the answer in correct scientific notation.
a) 8.95 x 1076/ 1.25 x 1056 b) (4.5 x 1029)(2.45 x 10100)
5. Give the number of significant figures in each of the following.
a) 1.05 g ______
b) 0.0003040 mm ______
c) 29000 + 10 ft ______
d) 0.90 x 1045 L ______
e) the number of eggs (12) that make up a dozen ______
6. Determine the answer for each of the following. Be sure to use the correct number of significant figures.
a) 17.34 b) 9.80
4.900 - 4.762
+ 23.1
c) 3.9 x 6.05 x 420 = d) 14.1 / 5 =
7. Round each of the following to 3 significant figures.
77.0653 ____________ 6,300,178.2 ______________
0.00023350 _____________ 10.2030 _______________
2.895 x 1021 ______________
Answers - Worksheet 2 |
7.27 x 102
1.72000 x 105
9.84 x 10-4
2.000 x 104
1.4
2.560 x 1033
2. Convert each into decimal form.
15600 + 100
0.036
73690000 + 10000
590 + 10
0.000059
3. Calculate the following. Give the answer in correct scientific notation.
a) 9.434 x 1066 b) - 8.87 x 102
4. Calculate the following. Give the answer in correct scientific notation.
a) 7.16 x 1020 b) 1.1025 x 10130
5. Give the number of significant figures in each of the following.
a) 1.05 g 3
b) 0.0003040 mm 4
c) 29000 + 10 ft 4
d) 0.90 x 1045 L 2
e) the number of eggs (12) that make up a dozen infinite
6. Determine the answer for each of the following. Be sure to use the correct number of significant figures.
a) 45.3 b) 5.04
c) 9.9 x 103 d) 3
7. Round each of the following to 3 significant figures.
77.1 | 6.30 x 106 |
0.000234 | 10.2 |
2.90 x 1021 |
Scientific Notation and Significant Figures Worksheet 1 with Answer keys
Worksheet 1 |
1. Convert each of the following into scientific notation.
a) 3427 | b) 0.00456 | c) 123,453 |
d) 172 | e) 0.000984 | f) 0.502 |
g) 3100.0 x 102 | h) 0.0114 x 104 | i) 107.2 |
j) 0.0000455 | k) 2205.2 | l) 30.0 x 10-2 |
m) 0.982 x 10-3 | n) 0.0473 | o) 650.502 |
p) 3.03 x 10-1 | q) 20.4 x 105 | r) 1.29 |
s) 0.00565 | t) 1362205.2 | u) 450.0 x 103 |
v) 1000 x 10-3 |
2. Determine the number of significant figures in each of the following:
a) 3427 | b) 0.00456 | c) 123,453 |
d) 172 | e) 0.000984 | f) 0.502 |
g) 3100.0 x 102 | h) 0.0114 x 104 | i) 107.2 |
j) 0.0000455 | k) 2205.2 | l) 30.0 x 10-2 |
m) 0.982 x 10-3 | n) 0.0473 | o) 650.502 |
p) 3.03 x 10-1 | q) 20.4 x 105 | r) 1.29 |
s) 0.00565 | t) 1362205.2 | u) 450.0 x 103 |
v) 1000 x 10-3 | w) 546,000 + 10 | x) 546,000 + 1000 |
3. Convert each into decimal form.
1.56 x 104 | 0.56 x 10-2 | 3.69 x 10-2 | 736.9 x 105 |
0.00259 x 105 | 0.000459 x 10-1 | 13.69 x 10-2 | 6.9 x 104 |
0.00259 x 103 | 0.0209 x 10-3 |
4. Calculate the following. Give the answer in correct scientific notation.
a) 4.53 x 105 b) 1913.0
+ 2.2 x 106 - 4.6 x 103
c) 2.34 x 1024 d) 2.130 x 103
+ 1.92 x 1023 - 6.6 x 102
e) 9.10 x 103 f) 1113.0
+ 2.2 x 106 - 14.6 x 102
g) 6.18 x 10-45 h) 4.25 x 10-3
+ 4.72 x 10-44 - 1.6 x 10-2
5. Calculate the following. Give the answer in correct scientific notation.
a) 3.95 x 102/1.5 x 106 b) (3.5 x 102)(6.45 x 1010)
c) 4.44 x 107 /2.25 x 105 d) (4.50 x 10-12)(3.67 x 10-12)
e) 1.05 x 10-26 / 4.2 x 1056 f) (2.5 x 109)(6.45 x 104)
g) 6.022 x 1023 / 3.011 x 10-56 h) (6.88 x 102)(3.45 x 10-10)
And here is the answer:
Answers - Worksheet 1 |
Left increase, right decrease
1. Convert each of the following into scientific notation.
a) 3.427 x 103 | b) 4.56 x 10-3 | c) 1.23453 x 105 |
d) 1.72 x 102 | e) 9.84 x 10-4 | f) 5.02 x 10-1 |
g) 3.1000 x 105 | h) 1.14 x 102 | i) 1.072 x 102 |
j) 4.55 x 10-5 | k) 2.2052 x 103 | l) 3.00 x 10-1 |
m) 9.82 x 10-4 | n) 4.73 x 10-2 | o) 6.50502 x 102 |
p) 3.03 x 10-1 | q) 2.04 x 106 | r) 1.29 x 100 = 1.29 |
s) 5.65 x 10-3 | t) 1.3622052 x 106 | u) 4.500 x 105 |
v) 1.000 x 100 = 1.000 |
a) 4 | b) 3 | c) 6 |
d) 3 | e) 3 | f) 3 |
g) 5 | h) 3 | i) 4 |
j) 3 | k) 5 | l) 3 |
m) 3 | n) 3 | o) 6 |
p) 3 | q) 3 | r) 3 |
s) 3 | t) 8 | u) 4 |
v) 4 | w) 5 | x) 3 |
15600 + 100 | 0.0056 | 0.0369 | 73690000 + 10000 |
259 | 0.0000459 | 0.1369 | 69000 + 1000 |
2.59 | 0.0000209 |
a) 2.7 x 106 | b) -2.7 x 103 |
c) 2.53 x 1024 | d) 1.47 x 103 |
e) 2.2 x 106 | f) -3.5 x 102 |
g) 5.34 x 10-44 | h) -1.2 x 10-2 |
a) 2.63 x 10-4 | b) 2.3 x 1013 |
c) 1.97 x 102 | d) 1.65 x 10-23 |
e) 2.5 x 10-83 | f) 1.6 x 1014 |
g) 2.000 x 1079 | h) 2.37 x 10-7 |
Tuesday, June 30, 2020
Thảo Luận Kỷ Năng Học-Hành-Thuyết (Pháp) của Thầy Đạo Sinh
Designed by Htr. Quảng Pháp |
NGƯỜI VỀ
NGƯỜI VỀ
Thư tòa soạn số 102, tháng 05, 2020
Trời rạng muôn phương với trăng sao
Đất rung bảy lần cùng núi rừng
Người về rực rỡ vườn tuệ giác
Thiên nhạc dặt dìu khúc xưng dương.
Trần gian thống khổ bao đời kiếp
Bảy bước đơm hoa mở đường về
Trí tuệ xua tan ngàn năm tối
Từ bi trải rộng vạn nẻo mê.
Thị hiện đi ngang đời tục lụy
Hóa độ hằng hà mộng phù sinh
Đại dương ảnh hiện trăng miên viễn
Dạt dào sóng vỗ nhịp vô thinh.
Từng đến từng đi từng lưu trú
Hay vẫn chưa từng với mộng trung (1)
Nhẹ cười phiêu diêu thân dặm lữ
Gậy trúc qua đường nghiêng bóng không.
Một thuở ngang về
Xôn xao cuộc thế
Căn nhà bốc lửa
Rường cột đổ nghiêng
Hớt hãi bầy đàn
Vẫn còn giành nhau ghế cao ghế thấp
Lặng nhìn thế sự trong đêm
Núi tuyết nghìn năm tịch mặc
Cánh phụng hoàng không lẫn giữa bầy quạ đen
Ôi đời, ôi thế nhân, hãy yên lòng tranh ngôi phù phiếm
Ta về đây không vì quyền chức, cao danh
Ta về đây mở một con đường
Con đường phủ nhận mọi con đường
Con đường cô liêu chỉ một hương vị
Tuyệt nhiên không lời
Bất động như như (2).
California, ngày 25 tháng 4 năm 2020
Kính dâng Thầy Tuệ Sỹ nhân mùa Phật Đản
Vĩnh Hảo
(1) “Như lai giả, vô sở tùng lai, diệc vô sở khứ, cố danh Như lai” (Như lai ấy không từ đâu đến, cũng chẳng đi đâu, nên gọi là Như lai. - Kinh Kim Cang).
(2) “Vân hà vị nhân diễn thuyết? Bất thủ ư tướng, như như bất động” (Thế nào là vì người diễn nói? – Không chấp nơi tướng, như như bất động. – Kinh Kim Cang)