Answer:
the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up. Example: 38 rounded to the nearest ten is 40
If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down. Example: 33 rounded to the nearest ten is 30
Rounding fractions works exactly the same way as rounding whole numbers. The only difference is that instead of rounding to tens, hundreds, thousands, and so on, you round to tenths, hundredths, thousandths, and so on.
By rounding off, you could easily figure out that you would need about $6.00 to pay for your groceries.
Which are not combination reactions?
Check all that apply.
A. 2H2O + 2H2 + O2
B. H2 + Cl2 → 2HCI
C. Fe + MgO + Mg + FeO
D. 2Na + Cl2 → 2NaCl
Answer:
A and c
Explanation:
In A the product is added to the reactant, so the real reaction is (2H2O = 2H2+O2).
In B hydrogen and clorine are combined to give hydrochloric acid and 2 is used to balance the reaction in the product, so it's a combination reaction .
In C the case is similar to A , so the real reaction is (Fe+MgO = Mg + FeO ) this is displacement reaction where a more reactive element takes place of a less reactive element .
In D sodium reacting with Chlorine to give sodium chloride ,so we conclude that it's a combination reaction .
True or False- Waves are caused by the water being pushed by the wind, which transfers energy, that can cause erosion to the shorelines .
Answer:
false
Explanation:
Waves are created because othe the lunar pull with out the moon we wouldnt have waves
When two objects are touching, thermal
energy transfers from...
hotter to colder substances?
Or
colder to hotter substances?
Answer:
According to the laws of thermodynamics, Molecular movements of particles will tend to move into state of lower energy and this would mean that knowing the vibrational and translational energy of complex molecules will lose and give off energy usually in the form of heat but also sound and other transferable mediums it will tend to become less energetic and this mobile indicative of colder objects, if examining the average Molecular kinetic energy and bond energies of the compounds in question.
Something that is made out of natural resources for human use is called
Answer:
Man-made resources
Explanation:
Humanized resources are items or substances that have value to human lives that do not occur in the natural world. Examples of man-made resources include plastic, paper, soda, sheet metal, rubber and brass. These contrast with natural resources, such as water, crops, sunlight, crude oil, wood and gold.
please help me with this question/
Answer:
4 of each protons and electrons
Explanation:
since the atomic number is 4 it would contain both the same number of protons and electrons
4 Na + O2 → 2 Na2O
6.79 moles of O2 will react to form how many moles of Na2O?
Answer:
13.94moles of Na₂O
Explanation:
The balanced reaction expression is given as:
4Na + O₂ → 2Na₂O
Given parameters:
Number of moles of O₂ = 6.97moles
Unknown:
Number of moles of Na₂O
Solution:
To solve this problem;
1 mole of O₂ will produce 2 moles of Na₂O ;
6.97 moles of O₂ will produce 6.97 x 2 = 13.94moles of Na₂O
How many moles are in 6.777 x 1023 atoms of CO2. Watch your significant figures. Question 2 options: 1 atoms CO2 1.125 moles CO2 1.13 moles 1.13 atoms CO2
Answer:
1.13moles
Explanation:
Given parameters:
Number of atoms = 6.777 x 10²³ atoms
Unknown:
Number of moles = ?
Solution:
A mole of a substance contains the avogadro's number of particles
6.02 x 10²³ particles = 1 mole
6.777 x 10²³ atoms will contain [tex]\frac{ 6.777 x 10^{23} }{6.02 x 10^{23} }[/tex] = 1.13moles
What is the Sl unit for energy? Be sure to give the full name for the unit
Answer:
Joules
Explanation:
True/False: Atoms of the same elements have different properties
Answer: True
Explanation:
4. How many moles of H, would be
produced from 47 grams of H2SO4?
2A1 +3H,504 → Al2(SO4)3 +3H2
Answer:
0.48 moles of H₂ are produced.
Explanation:
Given data:
Number of moles of H₂ produced = ?
Mass of H₂SO₄ = 47 g
Solution:
Chemical equation:
2Al + 3H₂SO₄ → Al₂(SO₄)₃ + 3H₂
Number of moles of H₂SO₄ :
Number of moles = mass/molar mass
Number of moles = 47 g/ 98 g/mol
Number of moles = 0.48 mol
Now we will compare the moles of H₂SO₄ and H₂
H₂SO₄ : H₂
3 : 3
0.48 : 0.48
Thus, 0.48 moles of H₂ are produced.
LAB REPORT
Lab: Charles law
I don’t know how to do this someone pls help I’m so behind I’m crying
Answer:
The physical principle known as Charles' law states that the volume of a gas equals a constant value multiplied by its temperature as measured on the Kelvin scale (zero Kelvin corresponds to -273.15 degrees Celsius
Explanation:
Which of the following locations will most likely have the highest rate of evaporation?
A. South Pole
B.Sahara Desert
C Atlantic Ocean
D Amazon rainforest
A 170.0 g sample of an unidentified compound contains 29.84 g sodium, 67.49
g chromium, and 72.67 g oxygen. What is the compound's empirical formula?
The empirical formula : Na₂Cr₂O₇
Further explanationGiven
170 g sample contains :
29.84 g sodium, 67.49 g chromium, and 72.67 g oxygen
Required
The compound's empirical formula
Solution
mol ratio of elements :
Na : 29.84 : 23 g/mol = 1.297
Cr : 67.49 : 51,9961 g/mol = 1.297
O : 72.67 : 16 g/mol = 4.54
Divide by 1.297
Na : Cr : O = 1 : 1 : 3.5 = 2 : 2 : 7
7. Although carbon's three isotopes are carbon-12, carbon-13, and carbon-14, its
average atomic mass is 12.01 because
A. carbon-12 is the heaviest isotope.
B. carbon-12 is most useful to humans.
C. carbon-12 is the most common isotope.
Answer:
B
Explanation:
carbon 12 is most useful to humans
Write the complementary RNA strand for the following DNA strand. TAC ACC TTG ACG
Answer:
ATG TGG AAC TGC
Explanation:
ATG TGG AAC TGC
which phrase best defines the term energy
Answer:
theres no options?
Explanation:
Balance the chemical equation. Based on the equation, how many grams of bromine are produced by the complete reaction of 11 grams of potassium bromide?
Answer:
Explanation:
The balanced chemical equation is Cl2 + 2KBr → 2KCl + Br2. The amount of bromine is calculated as follows:
11.0 g KBr (1mol KBr/119.002g KBr * 1mol Br2/2mol KBr * 159.808g Br2/1mol Br2= 7.39 g Br2.)
Does the following compound contain a polyatomic ion? LiC2H3O2
Yes
No
Answer:
yes
Explanation:
the polyatomic ion is acetate, C2H3O2
A compound has a molar mass of 100 g/mol and the percent composition (by mass) of 65.45% C, 5.45% H, and 29.09% 0. Determine the empirical formula and the molecular formula.
A) CHO and C6H6O6
B) C3H3O and C6H6O2
C) C3HO and C6H2O2
D) CH2O and C4H8O4
E) CH4O and C3H12O3
Answer:
B) C3H3O and C6H6O2
Explanation:
Given data:
Molar mass of compound = 100 g/mol
Percentage of hydrogen = 5.45%
Percentage of carbon = 65.45%
Percentage of oxygen = 29.09%
Empirical formula = ?
Molecular formula = ?
Solution:
Number of gram atoms of H = 5.45 / 1.01 = 5.4
Number of gram atoms of O = 29.09/ 16 = 1.8
Number of gram atoms of C = 65.45 / 12 = 5.5
Atomic ratio:
C : H : O
5.5/1.8 : 5.4/1.8 : 1.8/1.8
3 : 3 : 1
C : H : O = 3 : 3 : 1
Empirical formula is C₃H₃O.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = 12×3 + 1.01 ×3 + 16×1 = 55.03
n = 100 / 5503
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 (C₃H₃O)
Molecular formula = C₆H₆O₂
The answers plzzzzzzz
Answer:
ok, whats the question
Explanation:
A sample of oxygen is collected in a 175 mL container over water at 15°C, and the barometer reads 752.0 torr.
What volume would the dry gas occupy at 770.0 torr and 15°C? (Water vapor pressure at 15°C is 12.8 torr.)
The volume of dry gas = 168 L
Further explanationGiven
175 ml container at 15°C
P total = 752 torr
water vapour = 12.8 torr
Required
The volume of dry gas
Solution
Dalton's law of partial pressure :
P tot = P₁ + P₂ + P₃ ....
P total = P O2 + P water
P O2 = 752 - 12.8
P O2 = 739.2 torr
Boyle's Law
At a fixed temperature, the gas volume is inversely proportional to the pressure applied
P₁V₁ = P₂V₂
739.2 175 = 770 .V₂
V₂ = 168 L
1) How many atoms are in Molecules? O One O Exactly two O Two or more O Compounds don't have atoms
Answer:
Two or more!
Explanation:
a train is climbing a gradual hill. the weight of the train creates a downhill force of 150,000 newtons. friction creates an additional force of 25,000 newtons acting in the same direction (downhill). how much force does the train's engine need to create so the train is going uphill at a constant speed?
Answer:
25000 is the answer
Explanation:
The answer is 25000 hope this helps you
25,000N is the total force, the train's engine need to create so the train is going uphill at a constant speed.
What is force?A force in physics is an effect that changes the velocity of a mass-moving object, causing it to accelerate from rest, for example. It is a vector quantity since it can be a push or perhaps a pull and always has magnitude and direction. It is denoted by the letter F and is measured in newtons (N), the SI unit of force (formerly P).
The net force exerted on an object approximately equal to the rate where its momentum varies over time, according to the original formulation of Newton's second law.
The force by the train weight Fw= 150,000N
The force creates by the friction Ff=25,000N
total force =Fw + Ff
= 150,000N+25,000N
= 25,000N
Therefore, 25,000N is the total force.
To know more about force, here:
https://brainly.com/question/13014979
#SPJ2
What is the total magnification if we using objective lens 4x and our eyepiece (ocular) lens is 10x
40x
100x
400x
1000x
IF A CAPPED GLASS BOTTLE IS THROWN INTO A FIRE, WHAT WILL HAPPEN TO THE BOTTLE AND WHY?
Answer:
it will explode (not intensely) there is some oxygen in the bottle so the cap would pop off violently, the longer it stays in the fire the more energy is being pent up.
Explanation:
Answer:
The bottle will increase in both temperature and pressure which will cause the bottle to crack/shatter! Hope this helps :)
Explanation:
The law of Gay-Lussac states that as temperature increases so will pressure.
whoever answers first will get brainliest! this is times so pls help!
You are titrating a 125 mL sample of KOH solution; the pH meter reads 7.00 after the addition of 84.7 mL of 0.750 M HNO3.
What is the concentration of the KOH solution?
A. 0.125 M KOH
B.0.750 M KOH
C.0.508 M KOH
D. 0.0635 M KOH
thanks so much!
How many atoms are in 4.5 g of AICI3?
Answer:
2.047 × 10^22 atoms.
Explanation:
To calculate the number of atoms (nA) in AlCl3, we first need to find the number of moles in the compound, AlCl3.
Molar mass of AlCl3 = 27 + 35.5(3)
= 27 + 106.5
= 133.5g/mol
Using mole = mass/molar mass
mole = 4.5/133.5
mole = 0.034moles
number of atoms in a substance (nA) = number of moles (n) × Avagadros number or constant (6.02 × 10^23 atoms)
nA of AlCl3 = 0.034 × 6.02 × 10^23
nA = 0.2047 × 10^23
nA = 2.047 × 10^22 atoms.
By February of 1861, how many states seceded from the Union?
5
11
9
7
Answer:
D. 7
Explanation:
i did it
Does the following compound contain a polyatomic ion? CuCl2 *
Yes
No
Answer:
the answer is no
Explanation:
I don't no
Find the volume of a locker that is 30cm long, 40cm wide, and 200 cm high.
Answer:
V= L × W × H so the answer is 240,000