Answer:
d. compounds and elements
Explanation:
a pure substance is when something is made up of one type of thing, whether it be elements, where they are made up of one type of atom or a compound, where its atoms are chemically bonded and cannot be broken down by physical means
What is aluminum found in or used for? plz dont look it up
Answer:
Aluminum isn't found pure naturally, but its found mixed with other minerals in the earth. It's used to make cans, foil, kitchen utensils, window frames and even deodorant
Explanation:
The atomic radius of magnesium is 150 pm. The atomic radius of strontium is 200 pm. What is the atomic radius of calcium
Answer:
The atomic radius of calcium is approximately 175
Explanation:
Given that the atomic radius of magnesium = 150 pm
The atomic radius of strontium = 200 pm
Therefore, given that calcium comes in between magnesium and strontium in group 2 of the periodic table, the atomic radius should be half way between the length of the atomic radius of magnesium and strontium, given that the atomic radius is not a fixed quantity
Therefore;
The atomic radius of calcium is approximately given as follows;
The approximate atomic radius (200 + 150)/2 = 175 pm.
Use the information below to explain why the atomic radius decreases down a group.
Answer:
Detail is given below
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
In A we can see that there is one positive charge and force of attraction is 2.30×10⁻⁸ N and distance is 0.10 nm
In B we can see that negative charge is further away from nucleus because of greater distance thus force of attraction will be less. 0.58×10⁻⁸ N
In C this distance further increases and force also goes in decreasing 0.26×10⁻⁸ N.
If measurements are made, then they are more precise on a larger scale.?
Answer:
No.
Explanation:
According to the formula б/X=б/√n, as more measurements are made, the uncertainty gets smaller.
Explain in steps how to find volume of a rock that is not rectangular water displacement
What is the Scientific
Method?
Answer:
I just finished a unit on Scientific Method in my science class! Anyway, it's defined in the screenshots below. Hope this helps!
need help ASAP I will mark you brainiest if you answer!
If an egg is placed in a container of salt water, the mass of the egg will decrease because water will move out of the egg. What process does this represent?
Osmosis
Mitosis
Respiration
Fermentation
Answer:
osmosis. I
Explanation:
If an object/ cell is placed in a solution where the concentration is more or stronger than itself(hypertonic solution), it shrinks because water moves out of it, but if it is placed where the concentration of the surrounding solution is lesser than its concentration(hypotonic solution), it swells and can burst because water moves into it. So the mass of the egg will decrease because it is placed in an hypertonic solution (salt water) and the concentration of the salt water is stronger than its concentration
HURRY!! Solve. C3H8(g) + 5O2(g) --> 3CO2(g) + 4H2O(g)
What is the Enthalpy of reaction?
What is the total Enthalpy of Reactants and Products? (Kj/Mol)
Is this a endothermic or exothermic reaction?
Answer: hope this helps!
Explanation:
A proton is a subatomic particle carrying a charge equal to but opposite that of an electron
true
false
Answer:
True
Explanation:
A proton has a charge of +1, while an electron has a charge of -1. This is why a neutral atom has the same number of protons as electrons.
Neutrons have no charge, hence their name neutron which is similar to neutral.
Increasing the temperature of gas in a container that cannot expand is a way to _______. decrease the volume of the gas decrease the volume of the gas increase the pressure of the gas increase the pressure of the gas decrease the pressure of the gas decrease the pressure of the gas increase the volume of the gas
Answer:
Increase the pressure of the gas
Explanation:
According to the Pressure law, for a fixed mass of gas, at a constant volume (V), the pressure (P) is directly proportional to the absolute temperature (T).
From the kinetic molecular theory, gases are composed of particles which are in constant motion, colliding with themselves as well as with the walls of their container.
When the temperature of these gas molecules is increased, the molecules acquire more kinetic energy and the rate of collisions increases. Since the container cannot expand, the increase in pressure is due to the increase in collisions between the molecules of the gas as well as with the walls of their container.
Answer:
False
Explanation:
Its F
what is the heat of reaction H2 + 1/3N2 2/3NH3
which two is it if u get it correct u get brainlist
Answer:
The answer is D and B
Explanation:
It is a quanity because it is because it is being measured in terms of numerical information.
Its is also continuous beause it does not show random change in the mathmatics, it it a slow yet constant change of measurement.
15 Each Points Please Help ASAP!! View Attached Image!! Will Mark Brainliest If All Are Answered!!
Answer:
Questions 1 is Letters
Questions 2 is H I believe
Questions 3 is hardness
Explanation:
hope I helped
Answer:
1. c
2. a
3. b
you're welcome
Make a prediction about the relationship between electrons and molecular shapes
P.S WILL GIVE BRAINLIEST!
This occurs when energy is added or removed
Answer:
melting
Explanation:
Answer:
physical change
Explanation:
i googled it and that's what came up sry if it's wrong (change of state came up too if that doesn't work)
How many atoms are in 0.250 moles of Rb?
Answer:
1.51*10^23 atoms Rb
Explanation:
Use dimensional analysis
Express the following as a whole number or as decimals: 3.5 x 10-3 m
What are two substances that are useful because of their viscosity? (Please describe why they are useful)
Answer:
The two substances are Grease and Oil.
Explanation:
- Grease is used for other lubrication outside of the engine when it is really cold.
- Oil is used for lubricating when your engine is really hot.
tissues are made up of two or more different types of organs
Answer:
false
Explanation: An organ is a structure that is composed of at least two or more tissue types and performs a specific set of functions for the body.
plz mark brainliest
A 2.400-g sample of meat is subjected to Kjeldahl analysis. The liberated NH3(g) is absorbed by adding 50.00 mL of H2SO4(aq), which is more than enough. This occurs through the reaction 2NH3(g)+H2SO4(aq)→(NH4)2SO4(aq) The excess acid requires 19.90 mL of 0.5510 M NaOH for its complete neutralization.
Answer:
51.04% of protein in the sample
Explanation:
The question is the percentage of protein in the sample and the acid is 0.2496 M H2SO4.
First we need to calculate the moles of sulfuric acid that react:
Moles of sulfuric acid added:
0.0500L * 0.2496mol/L = 0.01248 moles of sulfuric acid.
Moles in excess:
0.01990L * 0.5510mol/L = 0.01096 moles NaOH * (1 mol H2SO4 / 2 moles NaOH) = 0.00548 moles of sulfuric acid.
Moles that react:
0.01248 moles - 0.00548 moles = 7.0x10⁻³ moles of H2SO4 react.
Based on the reaction, the moles of NH3 = Moles of N are:
7.0x10⁻³ moles of H2SO4 * (2moles NH3 / 1 mole H2SO4) = 0.014 moles NH3 = Moles N
The mass of nitrogen (Molar mass: 14g/mol):
0.014 moles N * 14g/mol = 0.196g of N.
The percentage of N is:
0.196g N / 2.400g = 8.17% of N
6.25 times the percentage of nitrogen is the percentage of protein:
8.17%*6.25 =
51.04% of protein in the sampleHow many kg is 59.0 mg?
Answer:
5.9e-5
Explanation:
How do we exist? What does scientific evidence suggest about the start of the universe?
Answer:
It all started with the big bang.
The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now (and it could still be stretching).
Can someone explain cellular respiration?
Answer:
Explanation:
set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules[1
Is the discharging of a battery producing electricity an Intramolecular force or Intermolecular force?
Answer:
I think its intermolecular
Explanation:
I'm sorry if it is wrong
Answer:
intermolecular forces
Explanation:
Draw arrows for all of the attractive and repulsive forces between the negatively charged electrons and positively charged protons in these atoms. Make sure your arrows clearly show the difference between attractive and repulsive forces. Note that the particles without a charge label are neutral.
Answer:
Attraction
(e-) ---> <--- (H+)
Repulsion:
<---(e-) (e-)-->
Neutral:
(e-) (Helium)
Explanation:
Accordingly to coulomb's law:
In the attraction, the hydrogen without an electron has a positive charge and needs to be fulfilled with a negative charge found in an eletron.
In the repulsion, both electrons has the same charge and repulse each other.
In the neutral case, the Helium is highly stable therefore the electron is not attracted.
Based on the oxidation states of the atoms in this reaction, answer the questions. 4Fe(0) + 3O2(0) → 2Fe2(3+)O3(2-) How many electrons does the iron half-reaction lose? How many electrons does the oxygen half-reaction gain? What is the total number of electrons that are moved in this oxidation-reduction reaction?
Answer:
Twelve electrons
Explanation:
If we look at the product side, we will notice that iron lost twelve electrons and oxygen gained twelve electrons.
Hence, we have 4Fe^3+ and 2O3^2- showing twelve electrons lost/gained.
Answer:
How many electrons does the iron half-reaction lose?
12
How many electrons does the oxygen half-reaction gain?
12
What is the total number of electrons that are moved in this oxidation-reduction reaction? 12
Explanation:
The east-west Schism resulted from a power struggle between the emperor and whom?
PLEASE HELP IM BEING TIMED
A:the pope
B:priests
C:bishops
D:The patriarch
Answer:
I'm pretty sure it is the patriarch
Explanation
Patriarch means the head of a family or tribe.
Answer:
D
Explanation:
An agronomist hypothesized that add ran intots
the growth of Bermuda grass seedlings. He
planted three samples of grass and watered each
with a different pH solution.
How did plant growth in the pH 3.1 group compare
to plant growth in the other groups?
Answer:
D
Explanation:
Answer:
1. D
2. A
Explanation:
How do I write the following :
One atom of Nitrogen
Five atoms of Nitrogen
One molecule of Nitrogen
Five molecules of Nitrogen
One molecule of Sulfur
One atom of Sulfur
Eight molecules of Sulfur
Answer:
Five molecules of nitrogen and eight molecules of sulfur
Explanation:
Which surface will most likely cause a rolling ball to slow down?A.grassB.iceC.tile
Answer:
grass
Explanation:
ice and tile are smooth and without any bumps or large ridges, unlike grass which is spiky and flexible. grass will most likely slow down a ball that is rolling, unlike answer choices B and C.
Answer:
grass
Explanation:
ice and tile are bothe a flat surface where grass has texture