Answer:
the noble gases
HELP IN 8TH GRADE ADV SCIENCE
Answer:
protons: 36
neutrons: 48
electrons: 36
A scientist thinks he found a new metal, so he published a paper about this metal. About 1 week after the scientist published the paper, you noticed a problem with the paper the scientist wrote. You noticed that this metal was not a new metal. In fact, this metal was discovered years ago. You determined this when you saw the atomic emission spectrum. As you read the article, you remembered that each atomic emission spectrum is unique to each element and the atomic emission spectrum matched one that was already discovered. Using the techniques from Chemistry, you ran a Flame Test with a piece of the metal (the metal is safe to use) that you had shipped to you. You found the metal turned the flame yellow. What metal did you have in your possession?
**ANSWER CHOICES**
*Barium
*Calcium
*Strontium
*Copper
*Sodium
Answer:
Sodium
because it burns with a yellow-orange flame.
Explanation:
It relates with Barium which burns with yellowish green flame
Which of the following best describes the velocity of an object?
A B0 m/s
B 30 m east
C 30 m/s east
D 30 m/s2
Answer:
[tex]\boxed {\boxed {\sf C. \ 30 \ m/s \ east}}[/tex]
Explanation:
Velocity is the vector measurement of the change in position over time. A vector measurement means the answer must include a magnitude (numerical value) and a direction.
Here are some units of velocity:
m/s (meters per second) kph (kilometers per hour) km/s (kilometers per second)There are many other units, but m/s is the most common.
We can eliminate choice B and D, because the units (meters-m and meters per second squared-m/s²) are not for velocity.
We are left with choice A (30 m/s) and C (30 m/s east). Remember, velocity needs a number and a direction. C contains the direction east, so it must be the correct answer.
What did you include in your response? Check all that
apply.
O No, thermal energy is not being transferred by
radiation in this image.
O The eggs are in direct contact with the metal pan,
which is in direct contact with the gas flame.
O Thermal energy is being transferred by conduction.
O Radiation transfers thermal energy by
electromagnetic waves.
O Radiation does not transfer thermal energy by
direct contact.
Are scientist improving the plant or corrupting it
Answer:
46 percent of trees have been cut down.
Scienctists helps plants, but humans do destroy a lot of plants.
Scientists - helps increase plant growth.
Woodchoppers - helps decrease plant growth.
PLEASE HELP !!
Use the diagram below to answer the following questions.
PLEASE HELP
E TE
Figure B
In Figure B, which region contains the noble gas family of elements?
ОА
OD
ОС
OB
Noble gas located in the region D
Further explanationNoble gas are located in group 18 in the periodic table consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), have a stable electron configuration where the valence electrons are 8(full outer shell of electrons), so it is very hard to react because of its stability
If we look at the periodic system of the elements, the noble gases are on the far right, so that in Figure 8 it is located in area D
And the other region :
A : alkali elements(group 1),
B : alkaline earth elements(group 2)
C : halogen elements(group 17)
Which of the following scenarios would not prompt the cell to start dividing
Answer:
what r the options??????
Please Help!
Which change takes place at the freezing point of a substance?
Group of answer choices
A. A gas becomes a liquid
B. A solid becomes a gas
C. A liquid become a solid
D. A gas becomes a solid
please also give me an explanation since I do not understand this.
Answer:
❤C. A liquad becomes a solid❤
Explanation:
✌When you freeze water its a scientific fact that it becomes solid.✌
An object is moving across a surface, but it does not gain or lose speed. Which best describes the object’s force?
Answer:
Explanation:
the vector sum of all such forces which equals zero for an object at rest. CASE 1: Considering a basketball of weight 1kg, if it has been kept stationary on the ground, there are two forces acting on it. These are it's weight (gravity) and equal and opposite force from the ground (normal reaction).
Answer:
The net force is zero. :)
Explanation:
What is environment?
Answer:
where an organism lives which includes everything that surrounds and influences the organism.
C3H5OH + 3 O2 --> CO2 + H2O When balancing the equation above, how many molecules of CO2 and H2O are produced? The first half is already balanced.
Answer:
1.8069*10²⁴molecules of CO₂ and H₂O are produced.
Explanation:
C₃H₅OH + O₂ → CO₂ + H₂O
The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.
Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts
Left side: 3 C, 6 H and 3 O.
Right side: 1 C, 2 H and 3 O.
The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.
By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.
So, balancing the C:
C₃H₅OH + O₂ → 3 CO₂ + H₂O
Then:
Left side: 3 C, 6 H and 3 O.
Right side: 3 C, 2 H and 7 O.
Now, balancing the H:
C₃H₅OH + O₂ → 3 CO₂ + 3 H₂O
Then:
Left side: 3 C, 6 H and 3 O.
Right side: 3 C, 6 H and 9 O.
Finally, balancing the O:
C₃H₅OH + 4 O₂ → 3 CO₂ + 3 H₂O
Then:
Left side: 3 C, 6 H and 9 O.
Right side: 3 C, 6 H and 9 O.
Since you have the same amount of each element on each side of the reaction, the reaction is balanced. Then 3 moles of CO₂ and 3 moles of H₂O are produced.
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole and it applies to any substance.
Then the following rule of three applies: if 1 mole contains 6.023*10²³ molecules, then 3 moles of CO₂ or 3 moles of H₂O, how many molecules does it contain?
[tex]amount of molecules=\frac{3 moles* 6.023*10^{23} molecules}{1 mole}[/tex]
amount of molecules= 1.8069*10²⁴
1.8069*10²⁴ molecules of CO₂ and H₂O are produced.
Which substance is correctly identified as a homogeneous or heterogeneous mixture?
A. salad -- heterogeneous
B. milk --- heterogeneous
C. river water --- homogeneous
D. beach sand --- homogeneous
Answer:
A
Explanation:
A salad with lettuce, cheese, seeds, tomatoes, broccoli, and other vegetables is an example of a heterogeneous mixture.
Milk is not mixed with anything so that is incorrect
River water is mixed in with dirt and minerals so this one is incorrect
Beach sand is incorrect because you can see colored particles.
What would happen if a neutron was added to Lithium (7)
Answer:
if you add a neutron to lithium-7 it becomes a compound nucleus of lithium-8