CHEM 101 ch 1-3c
which is the coldest temperatures 100 F 100 C 100 K
100 K F freeze is 32 C freeze is 0 K freeze is 273.5
how many oxygen atoms are in 25 molecules of dinitrogen tetroxide, N_²O_⁴
100 atoms
the prefix kilo - denotes what multiple of a basic unit? 10000x 10x 1,000x 100x
1000x
what's the difference between deca (10^1), and hecto (10^2)? 10x 100x 1,000x
10x wherever you move, up, or down, on the SI Chart the measurement your on doubles.
determine the number of protons (p) and electrons (e) in Mg²+
12 protons 10 electrons cation
sulfur-33 has how many protons and neutrons
17 N 16 P
skip conversion factor would you use to convert the number below to the new desired unit? 46kg 》》g
1x10^3g/1kg (use cheat sheet properly)
if the answer to the following math problem would have how many significant figures? 13.1 x 72=
2 significant figures
convert 14° C to K
287 K (k= c+273)
3.45 kiloliters (KL) is equal to how many liters?
3,450
an atom has 15 protons and 16 neutrons and 14 electrons. What is its mass number?
31
determine the number of protons (p) and electrons (e) found in Se²-neg- ion
34 p 36 e anion
185,007 / 5,301 =? (don't need calculator. this tests significant number knowledge) 34.9 34.90 34.9004
34.90 because 5,301 is the smallest number and contains only 4 sig digits. so you answer with 4 digits.
what is 67 degrees C expressed in Kelvin
340 k (k= c +273)
how many significant figures does the following number contain? 2004 1 2 3 4
4
convert the following into standard 4.07x10^5
407,000
The number 4.29 × 10⁴ when taken out of scientific notation would be
42900
you determine the density of an unknown solid is a 2.45 g/ml. How much does 18.1 mLs of an unknown solid weigh in grams?
44.4 g
which conversion factor would you use to convert the number below to the new desired unit? 7.2 lb 》》g
463.59g / 1lb (use cheat sheet properly)
complete the following equation and provide the answer with correct significant figures? equation: 136.4x3.51 =
479 (3 significant figures)
what is the atomic number of an element whose mass number is 78, which contains 30 neutrons per atom?
48 (mass number) - (neutrons)= atomic number/protons
how many significant figures are in the following value? 0304.01
5
how many significant figures is in 50.260?
5 significant figures. significant figures are 1) non-zeros, 2) trapped zeros between sig fig in a decimal (trapped/buried zeros), and 3) if the number is in scientific notation. they are insignificant when 1) leading, or 2) trailing not by a decimal
an unknown element X has the following Isotopes: 52x what was (89.00% abundant), 49x (8.00% abundant), 50x (3.00% abundant). What is the average atomic mass in amu of x (need calculator)
51.7 amu formula: ((1 isotope abundance x mass of 1 isotope) + (2 isotope abundance x mass of 2 isotope))/100
which of the following is standard notation 521 5.248 x 10^4
521
complete the following equation and provide the answer with correct significant figures. equation: 1.369 / 0.234 =
58.5 (leading zeros aren't significant making only 3 significant figures)
The number 0.000741 written in scientific notation would be? 7.41x10^4 7.41x10^-4
7.41 × 10⁻⁴
The number 875000 written in scientific notation would be
8.75x10^5
how many meters are on 0.886 km -significant figures -dimensional conversion -put in standard notation
886
The number 98000 written in scientific notation would be 9.8x10^4 9.8x10^-4
9.8x10^4
it turns out the dark side of the moon has a mean temperature of -280⁰ Fahrenheit. what would the temperature be on the Kelvin scale?
99.8 K or 100 K
Anion
A negatively charged ion (gained electron to gain full valance)
Cation
A positively charged ion (gave electron away for full valence)
The density of water is approximately 1 g/cm³. Which of these objects will float on water? nylon D=1.150 g/cm^3 diamond D= 3.5g/cm^3 Cedar wood block D= 0.380 g/cm³
A) Cedar wood block, d = 0.380 g/cm³
sulfur monoxide is.... A) Molecule and compound B) Atom and compound C) Molecule but not a compound D) Molecule and mixture
A) Molecule and compound
element symbol for arsenic is...
As (using periodic table)
which of the following is not a postulate of the atomic theory? (pick the statement thats false) A) Atoms cannot be created or destroyed. B) All atoms of an element must contain the same number of electrons and neutrons. C) Matter is composed of small particles called atoms. D) Matter atoms of one element different properties from atoms of all other elements.
B) all atoms of an element must contain the same number of electrons and neutrons
which has a greater mass? A) electron B) proton
B) proton
Which will have a higher density: 1.00 g of pure gold or 1.00 kg of pure gold? 1 g 1 kg same density no way t determine
Both will have the same density *(Density is an intensive property - it is the same no matter the amount of a given substance you have. It is a ratio of mass to volume, so as mass grows, so will volume at the same rate for a given substance.)*
density formula
D=m/v (density = mass/volume)
Which of the following metric prefixes corresponds to 10³?
Kilo-
Which of the following metric prefixes corresponds to 10⁻³?
Milli-
element symbol for nickel is...
Ni (using periodic table)
what does the mass number of an atom represent?
Number of protons and neutrons
The density of water is approximately 1 g/cm³. Which of these substances will sink in water? polymer resin, d = 1.03 g/cm lithium, d=.535g/cm^3 liquid hydrogen, d= 0.070g/cm^3
Polymer resin, d = 1.03 g/cm
what is the equivalent to 3.7 cm in km?
Solution: 1 centimeter is equal to 0.01 meters, 10 millimeters, 10,000 micrometers, and 1×10^-5 km. Convert cm to km.
3333 is divided by 5.0 the answer should have two significant figures. true or false
True
all the conversions you will need for this class are provided on your cheat sheet. True or false
True
conversion factors change the units but not the total amount of what is being measured. True or false
True
homogenous mixtures often appear to look like pure substances. True, or false
True
when converting 289.3 into a scientific notation, the exponent would be positive. True or false
True
the mass of an object is
a measure of the amount of matter in the object
Exact number is...
a number that is either defined, or can be counted. ex. There are 10 people in the room, but if a apple weighs 10 grams, it doesn't count because you cant count the grams.
the smallest subdivision of matter is... compound pure substances atom element
atom
number of protons is the....
atomic number
the weighted average of all isotopes is...
atomic/molecular weight
which statement is false? a) The majority of the mass of an atom is found in the nucleus b) neutrons are tiny compared to protons and electrons . c)electrons are tiny and have a negative charge.
b) neutrons are tiny compared to protons and electrons
Three blocks of the same mass are placed in front of you. Block A has a volume of 3.0 cm³, block B of 5.0 cm³ , and block C of 10.0 cm³ . Which has the higher density?
block A
Three blocks of the same shape and size are placed in front of you. Block A has a mass of 3.0 g, block B is 5.0 g, and block C is 10.0 g. Which has the higher density?
block C
the atomic number of an atom can be found...
by the number of protons and top left of element square
cation vs anion
cation: positively charged ion anion: negatively charged ion
Chemical or Physical change? digesting food
chemical
Chemical or Physical change? scrambling/ cooking eggs
chemical
table salt (NaCl) is best classified as a... heterogeneous mixture element a homogeneous mixture compound
compound
Whenever two numbers are equal to each other in chemistry we can use them as a...
conversion factor
Density is defined as mass _____________ volume.
divided by
which of the following particles is the smallest? proton electron Neutron
electron
isotopes of an given element have different numbers of protons (atomic numbers) true or false
false
mass is affected by gravity while weight is not. True, or false?
false
salt water would be classified as a /an? heterogeneous mixture element homogenous mixture (solution) compound
homogenous mixture (solution)
Water has a density of 1.00 g/cm³, whereas cooking oil has a density of 0.93 g/cm³ and the ice cube had a density of 0.917 g/cm³. Which of the following correctly orders the layers in a mixture of cooking oil, water, and ice? (top-bottom) water, oil, ice ice, oil, water oil, ice water
ice oil water *the lightest floats*
the number of significant figures derived from a measurement is....
limited by the exactness of the measurement tool
match the property with the name of the corresponding unit. mass -? amount of substance -? density -?
mass - grams amount of substance - mole (mol) density - M/V
mass number vs atomic mass (amu)
mass number: p+n amu: average mass of all the isotopes of an element
Which of the following metric prefixes corresponds to 10⁶?
mega-
What is the name of the SI unit for length?
meter
neutral atoms of all isotopes of a given element have the same...
number of electrons and protons **Isotopes are forms of the same element that differ in the number of neutrons they contain the same number of protons and electrons**
measurement tools allow for estimation of...
one uncertain digit
which is an element? human body oxygen carbon monoxide (CO)
oxygen
An atom of the isotope chlorine-39 consists of how many protons, neutrons, and electrons? (p = proton, n= neutron, e = electron)
p =17 n=22 e=17
Chemical or Physical change? ice cube melting
physical
A mass number is...
protons + neutrons = the mass #
the nucleus of an atom contains...
protons and neutrons
Vegetable oil has a density of 0.92 g/cm³. Which of these substances would float on vegetable oil? corn syrup, d= 1.4g/cm aluminum, d= 13.6g/cm rubbing alcohol , d= .79g/cm
rubbing alcohol , d= .79g/cm
common name for a liquid homogenous mixture? alloy mixtures compound solution
solution
Kelvin is the SI unit for which physical quantity?
temperature
A chemist has a block of aluminum metal (density is 2.7 g/mL). The block weighs 1.5 g. What is the volume, in mL, of the aluminum block? (need calculator) d=m/v
0.56 mL or also 0.555555556 mL
how many grams are in 778.7 mg? -significant figures -dimensional conversion -put in standard notation
0.779 (4 significant figures)
the answer to the following math problem will have how many significant figures? 400 X 3.045=
1
the answer to the following math problem would have how many places right of the decimal (PRD)? 897034.8 - 588.43=
1
The number 8.72 × 10⁻³ when taken out of scientific notation would be
0.00872
The density of diamond is 3.51 g/cm³. What is the volume (in cm³) of a 1-karat diamond with a mass of 0.200 g? (need claculator) d=m/v
0.056980057 cm³ or also 0.0570 cm³
A chemist encounters an unknown metal. They drop the metal into a graduated cylinder containing water, and find the volume change is 4.1 mL. If the metal weighs 2.1 g, what is the density of the metal in g/mL? (need calculator) d=m/v
0.512195122 g/ml
you are working with newly discovered liquid sample. It has a volume of 40.5 ml and a mass of 21g. What is the density?
0.52 g/ml *the decimal on right doesn't count as sig fig* (density= mass/volume)
atomic weight formula
( isotope 1 (mass x weight) ➕ isotopes 2 (weights × mass) ) /100
how many grams is 65.3 milligrams (mg)?
.0653
you're given a piece of clay that has a volume of 57.4 mL and has a mass of 3.9 grams. what is its density in g/ml -significant figures
.068 trailing zeros only count when they're right of the decimal
A chemist has a block of gold metal (density is 19.3 g/mL). The block weighs 3.10 g. What is the volume of the gold block in mL? need calculator d=m/v
.161 ml
elements are made of only one type of atom while compounds are made of more than one type of atom. true or false?
true
true, or false? To abide by the atomic theory there must be the same number of each type of atom on both sides of a chemical reaction
true
