the answer is : False
just did it
Match these items.
1. bring blood to the heart .veins
2. major artery bringing blood from the heart to the body .ventricle
3. doorways to the heart .aorta
4. measure of the rate of heart contractions .pulse
5. heart passageway to the arteries. valve
6. passage to the ventricle .atrium
Answer:
1- veins
2-aorta
3-valve
4-ventricles
5-atrium
The percent composition by mass of nitrogen in NH OH (gram-formula mass = 35 grams/mole) is equal to
Answer:
the percentage composition of mass of nitrogen in NH OH is 42.86 %
Question 2 (1 point)
Which of the following does NOT involve a chemical reaction?
Fallen leaves decay in a compost pile.
Leaves change color in the fall.
O A fire burns a pile of fallen leaves.
A pond freezes over in the winter.
Answer:
D. A pond freezing over is not a chemical reaction, it is a physical reaction.
Which of the following statements best describes a
mixture?
O A substance that contains two or more elements chemically joined
O A substance that contains two or more elements not chemically joined
O A substance that contains only one type of atom
O A substance that contains two or more compounds or elements that are
not chemically joined.
Where are new volcanoes in the Hawaiian island chain forming
Answer:
The Hawaiian Islands are a very small section of a huge chain of volcanic islands that crosses the northern half of the Pacific Ocean, called the Hawaiian-Emperor Volcanic Island Chain, which is over 6,000 kilometres long. The chain is linear, with a large bend in the middle: the southern half is called the Hawaiian Ridge and the northern half is called the Imperial Seamount.
Explanation:
How many moles are in 2.5L of 1.75 M Na2CO3
Answer:
4.375 moles Na2CO3
Explanation:
Formula for molarity is;
M = n/V
Where;
M is molarity
n is number of moles
V is volume
Making n the subject we have;
n = VM
We are given;
M = 1.75 M
V = 2.5 L
Thus;
n = 2.5 × 1.75
n = 4.375 moles Na2CO3
Answer:
4.375 moles Na2CO3
Explanation:
Have a great day
what energy is walking?
A. light energy
B. sound energy
C. Thermal energy
D. Mechanical energy
E. electrical energy
Answer:
Mechanical
Explanation:
Which statement best describes the energy in the food web? A. The amount of energy available at level B depends on the amount of energy available at level C. B. The amount of energy available at level A depends on the energy provided from an abiotic source. C. The amount of energy available at level C is greater that the amount of energy available ate level A. D. The amount of energy available at level B is transferred to level A
Answer:
The amount of energy available at level A depend on energy provided from an a biotic source
How many molecules are in 13.2 L F2
Answer:
3.55 x 10^23 molecules F2
Explanation:
molecules = moles x avogadro number
1 mole of gas occupies 22.4 L
moles of F2 = 13.2/22.4= 0.589 moles
moles F2 = 0.589 x 6.022 x 10^23 = 3.55 x 10^23 molecules F2
HELPPP HURRY FIRST GET BRAINLEST The rusting of steel wool occurs when the iron in the steel wool combines with what substance?
carbon dioxide
hydrogen
nitrogen
oxygen
Answer:
iron oxide. aka. oxygen
Explanation:
Rust is the result of a chemical reaction between iron and oxygen, otherwise known as iron oxide. Since steel wool -- and steel in general -- is largely made of iron, steel wool is prone to rust if it doesn't have a rustproof coating on it. The actual reaction that creates rust happens when two iron atoms mix with three oxygen atoms in water; the oxygen bonds to the metal, and a new compound is formed.
Please help me thanks
Answer:
your finger becomes negatively charged
Explanation:
hope it helps. follow me
Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose C6H12O6 and oxygen O2 gas. Calculate the moles of oxygen produced by the reaction of 0.800mol of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to 3 significant digits.
Answer:
0.800 mol of O2
Explanation:
Calculate the moles of oxygen produced by the reaction of 0.800mol of carbon dioxide.
The balanced equation for the reaction is given as;
6CO2 + 6H2O → C6H12O6 + 6O2
From the reaction;
6 mol of CO2 produces 6 mol of O2
0.0800 mol of CO2 would produce x mol of O2
6 = 6
0.0800 = x
Solving for x;
x = 6 * 0.800 / 6
x = 0.800 mol
what is the percentage composition of carbon and hydrogen in ethane(c2h6,molecular mass 30.0)
Answer
% of C in C2H6= (2×12)/30×100=80%
% of H in C2H6= (3×2)/30×100=20%
Explanation:
2C+3H2-C2H6
nC=12, nH=1, nC2H6=30
2moles of C-1mole of C2H6
3moles of H-1 mole of C2H6
% of C in C2H6= (2×12)/30×100=80%
% of H in C2H6= (3×2)/30×100=20%
If 4 moles of sulfur reacts with 9.5 moles of oxygen, how many moles of oxygen would remain after the reaction ?
We obviously cannot wait for million years to determine the half-life of technetium, or even years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of pulses and a count of pulses minutes later.
The question is incomplete, the complete question is;
We obviously cannot wait for 4 million years to determine the half-life of technetium, or even 87.7 years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of No pulses and a count of N1 pulses M minutes later.
Answer:
M1/2 = 0.693/k
Explanation:
Given that the initial count rate is No pulses
The count rate after M minutes is N1
Then from;
A = Aoe^-kt
A= N1
Ao=No
I can now write;
N1 = Noe^-kM
The half life is the time taken for the activity of the radioactive nuclide to reach half its initial value. Hence;
N1/No =e^-kM = 1/2
Taking natural logarithm of both sides as shown below;
-kM1/2 = ln(1/2)
M1/2 = - (ln(1/2)/k)
M1/2 = 0.693/k
a change of state does not affect an object's what.
Answer:
Mass
Explanation:
Which best describes the process that occurs when liquid water becomes
ice?
Answer:
Freezing
Explanation:
When a liquid goes to a solid, this process is called freezing.
Answer:
The water molecules get condensed and form a solid matter called ice. This process is called Condensation.
AWNSER FAST PLEASE
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(awnsers H²O -> (awnsers H² -> (awnsers O²
awnser for all drop-down menus 1,2, or 3
Answer: The coefficients are 2, 2 and 1.
Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants.
The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for the given reaction is:
2H2o➡️2h2+o2
help please i need this
Laura can use a toy car to demonstrate the force of gravity by doing which of these?
Letting the toy car roll down a ramp
Placing the toy car on the floor
Lifting the toy car onto a shelf
Pushing the toy car across a table
Answer:
letting the car fall down the ramp i got that right.
Explanation:
Which part of a calcium atom in the ground state is represented by the dots in its Lewis electron-dot diagram?
Answer:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom.
Explanation:
True or False: The specialized cells in a UNICELLULAR organism perform
specialized jobs.
Your answer
Answer:
True
Explanation:
What is the molar mass of AIC13?
PLLLzzzzzzzz helpppp Which is correct lab safety? A) Rodney wafted the fumes produced during the reaction toward his nose. B) Andrew heated the test tube towards himself in order to better observe the reaction. Eliminate C) Kadie was aware of the lab procedures that day so she began the lab before the rest of the class to be sure she would finish. D) Suzanne did not use all of the sulfuric acid she poured out for the experiment, so she returned the remainder to the stock bottle.
Answer:
A
Explanation:
can i get brainliest pls
The smallest arteries in your body are called _____. arterioles capillaries veins bronchioles
Answer: arterioles
Explanation:
help please will give brainly if right
Answer:
B and D
Explanation:
Because its adaptions they need to survive in the cold.
How many grams of AlCl3 will be produced if 3.85 moles of Al react? Al + ___Cl2 → ___AlCl3
Answer:
513.975g
Explanation:
I'm assuming that the question has Aluminium and Chlorine as the question is not clear.
1. Balance the equation
2 Al + 3 Cl2 → 2AlCl3
2. Use the mole = mass/mr equation and molar ratio to find the mass of AlCl3
133.5 x 3.85 = 513.975g
Definition: This is a net gain or loss of electrons.
Example: Your hair gains one when you pull a wool sweater over your head.
res)
Term:
Answer:
Elecric charge/ Electricity
Explanation:
Electric charge is the net gain or loss of electrons
I hope im right!!
If I have 2.500 grams of magnesium how many moles of magnesium do I have?
Answer:
0.1029(rounded to sig figs)
Explanation:
convert from grams to moles
Amount in grams/molar mass of substance
Molar mass of Mg=24.305
So, 2.500/24.305=0.1028594939
Rounded to 0.1029
what grade percentage is developing, proficient, exceeding, and emerging?
Answer:
Grade A is the best percentage that is developing, proficient, exceeding, and emerging