Where did you put H an He? What are your reasoning for placement?

Answers

Answer 1

Answer:

On the placement of hydrogen and helium in the periodic system

H1=1

He2=2


Related Questions

D
Question 3
1 pts
In olden times, apothecaries used to dispense medicine using their own system of measurements
that are listed below. Use these conversions to determine how many milligrams would be in a
sample of 1.250 scruples.
1 apothecary pound = 12 ounces
1 ounce = 8 drams
3 scruples = 1 dram
1.2153 apothecary pound = 1 English pound
1 kg = 2.205 English pounds
Enter your answer to the correct number of significant digits. Do not include the units.

Answers

Changing 1.250 scruples to milligrams.

To convert from a unit to another, First write the conversion guide

then cross multiply in such a way that the  unit  both top and bottom

cancel out each other together with dividing or multiplying  the values associated with them.

To get to the answer we have to wor it out step by step.

First step

3 scruples = 1 dram

1.250 scruples=

= [tex]\frac{1.250 scruples x 1 dram}{3scruples}[/tex] = 0.41667dram

2nd step

8 drams=1 ounce

0.41667drams   =

[tex]\frac{0.41667drams x 1}{8 drams }[/tex]  =0.05208 ounces

3rd step

1 apothecary pound = 12 ounces

?apothecary pound =0.05208 ounces

[tex]\frac{0.05208 ounces x 1apothecary pound }{12 ounces}[/tex] =0.00434 apothecary pound

4th step

1.2153 apothecary pound = 1 English pound

0.00434 apothecary pound =

[tex]\frac{0.00434 apothecary pound x 1 English pound}{1.2153 apothecary pound }[/tex] 

==0.003571 English pound

5th step

1 kg = 2.205 English pounds

 ??kg      =0.003571 English pound

[tex]\frac{0.003571 English pound x 1kg }{2.205 English pounds}[/tex]

=0.00161950kg

6th step

1kg =0.00161950kg

0.00161950kg=

[tex]\frac{0.00161950kg x 0.00161950kg}{1kg}[/tex]

=1,619.50mg

Therefore, 1.250 scruples=1,619.50mg

See related type of question here:

https://brainly.com/question/21946442

All of the following are examples of simple tools except:

A.magnifying glass

B.space telescope

C.pulley

D.lever

Answers

Answer:

space telescope I assume

Explanation:

all other tools can be made and used very easily but a telescope took years and years to invent

4(a) Why doesn't the water flow out when the hand that presses the cardboard is removed? *

1. water inside glass is lighter
2. there is much water inside the glass
3. cardboard is supported by air pressure
4.
cardboard is strong enough to hold the water

Answers

Air pressure is the weight of a column of air pushing down on an area. ... Because of the air pressure pushing up on the card, the card will stay on the glass and the water will not spill out.

Are ALL acids and based
harmful to humans?

Answers

No they aren’t all harmful there are acids like citric acid that are ok to consume

which is the best interpretation of the two flat portions of the graph

A. These show where kinetic energy is increased

B. These show where temperature is at 0 Celsius

C. These show where thermal energy does not exist

D. These show were changes of state are occurring​

Answers

Answer:

b

Explanation:

since Y axis is the temperature axis, flat portion meaning that there is no increase in temperature. and in this section, what’s happening is only change of state. at 0 degrees ice (solid water) is changing into liquid water. and at 100 degree, liquid water is changing to water vapor

In the adjoining figure, the circles with the + sign represent protons and the empty circles represent neutrons. Determine which atoms in the figure are isotopes of each other.

Answers

Answer:

2 and 3 explanation in the comments

Which functional group does the molecule below have?
A. Ether
B. Amino
C. Carbonyl
D. Hydroxyl
SUBV

Answers

Answer:

Ether is the correct answer

Explanation:

It is based.

Which of the following statements best defines the actual yield of a reaction? (5 points)

Select one:
a.The amount of product measured after a reaction
b.The ratio of measured yield over theoretical yield
c.The maximum amount of product that can be obtained Incorrect
d.The ratio of measured yield over stoichiometric yield

Answers

Answer:

its d

. . . . . . . .. . . . . . . . .. .

9. SI base units used in chemistry include
A. kilograms, liters, inches, and moles.
B. pounds, gallons, moles, and Fahrenheit.
C. kilograms, seconds, moles, and Kelvin.
D. pounds, gallons, moles, and Celsius.

Answers

Answer:

C. kilograms, seconds, moles, and Kelvin

Iron has a density of 7.86 g/cm3. Calculate the volume (in dL) of a piece of iron having a mass of 4.59 kg .

Answers

Note:
k = 10^3
1 cm^3 = 10^-2 dL

Solutions

Density = (mass)/(volume)
Volume = (mass)/(density)
Volume = (4.59 × 10^3g)/(7.68g/cm³)
Volume = 583.97 cm³
Volume = (583.97 cm³)(10^-2 dL/1 cm³)

So volume = 5.84 dL approximately

As the human population has grown. Earth's ecosystems and the balance
of natural cycles have been negatively affected. What are some
examples of how the social factors of sustainability (Fig. 1-3) could be
used to help repair environmental damage caused by humans?
40 POINTS I NEEDA ASAP

Answers

Some of the negative affects are oil spills from company’s, Air pollution from big factors and landfills.

Some social factors that could repair environment damages can be decomposable plastic. Such as plastic bags, plastic cups and containers.

calculate the number of moles in 2.5 particle NaOH

Answers

Answer:

1.5055×10²⁴

Explanation:

................................

a 2.00 mL sample of a substance A has a density of 18.4g/mL and a 5.00 mL sample of substance B has a density of 35.5g/mL. do you have an equal mass of substances A and b?

this question made my brain hurt. please explain :(

Answers

Answer:

no

Explanation:

make use of this formula to find the mass of each sample.

m=density*volume

How many molecules are their in o.5 mole of H2o

Answers

Answer:

There are 6.022x10^23 molecules

The unknown metal ion gave a yellow/orange flame test and no precipitate with ammonium carbonate. What is the unknown metal?

Answers

Answer:

Sodium

Explanation:

Which of the following represents the electronic structure of three elements in the periodic table

A. 2.8.1 2.8.3 2.8.4 B. 2.8 2.8.1 2.8.2
C. 2.7 2.8 2.8.1 D. 2.1 2.8.1 2.8.8.1

Answers

Answer:

a

Explanation:

idieiiwwjjwjwjwissisisieiwiwiजिदिेिौिेजदजेजेनसनजसझधिै

True or False
A sphere is a group of parts that work together as a whole.

Answers

false
hope this helps :)

False is the correct answer.

If a stronger solution of sodium bicarbonate was used in beaker C, would it require more or less hydrochloric acid to neutralize and why?

Answers

Part A; A stronger solution of sodium bicarbonate require more hydrochloric acid will be required

Part A; The reason why more HCl is required is due to the presence of more hydroxyl ions in the solution

The reason arriving at the above responses are as follows;

Part A

Sodium bicarbonate, NaHCO₃, is baking soda = A basic salt; has the capacity to deprotonate water

Hydrochloric acid, HCl = An acid

The reaction between sodium bicarbonate and hydrochloric acid is presented as follows;

NaHCO₃ + HCl → CO₂ + H₂O + NaCl

The equation for the ionic reaction is as follows;

Na⁺(aq) + HCO₃⁻(aq)  + H⁺(aq) + Cl⁻(aq)  → Na⁺(aq) + Cl⁻(aq) + H₂O(l) + CO₂(g)

In water, we have;

HCO₃⁻(aq) + H₂O(l) ⇄ H₂CO₃(aq) + OH⁻(aq)

The presence of a stronger solution of sodium bicarbonate, will produce more hydroxyl ions, OH⁻(aq), which will require, more HCl to neutralize

Therefore, if a stronger solution of sodium bicarbonate was used, more hydrochloric acid will be required

Part B

The solution of stronger sodium bicarbonate will contain a higher concentration of hydroxyl ions and therefore, require more HCl, to neutralize

Learn more about acid base reaction here:

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What is kaleidoscope? Write it's use .​

Answers

Answer:

Kaleidoscope is an optical toy consisting of two mirrors at a particular angle. Some common uses of the kaleidoscope are: Kaleidoscope produces beautiful patterns that are used by fashion designers. A kaleidoscope is used as a toy for entertainment.

Hope it's helpful

Filtration is the most appropriate method for separating a solution of water and which substance?

A. alcohol

B. salt

C. sand

D. sugar

Answers

Answer:

Sand

Explanation:

If you get salt or sugar in your water, you have to legit desalinate it to get the water and item out. You need to evaporate the water by increasing temperature and then lower temperature to separate the substances.

If you have alcohol, you need to distill it by trapping it and stuff.

With sand, the molecules are much larger which lets you separate the substances easily.

For example, on a beach, you can slap a handful of sand in your pail, but the sand sinks to the bottom right? You can just pour out the water.

All living organisms are made of
They are the smallest units of a living.
thing that can perform all life processes.
A. stones
B. cells
C. water drops
D. bricks

Answers

The answer to the question is cells (B)

Nonmetallic materials that are strong, brittle, resistant to heat and attack by chemicals, and are typically made from clay are known as:________

Answers

nonmetallic materials following that description is ceramics

In this question you should assume that all gases behave ideally.
Hydrogen and iodine react reversibly in the following reaction. The system reaches dynamic
equilibrium.
H2(g) + I2(g) 2HI(g) ∆H=–9.5kJmol–1 Which statement must be true for the Kp of this equilibrium to be constant?
A The partial pressures of H2, I2 and HI are equal.
B The external pressure is constant.
C The forward and reverse reactions have stopped.
D The temperature is constant.

Answers

Answer:

B

Explanation:

The number of moles of each reactant is equal, there by pressure has no effect on the chemical system. Pressure is constant

Al(s) + NaOH(aq) → Al(OH)3(s) + Na+(aq) displacement, or decomposition.

Answers

Answer:

Displacement

Explanation:

OH- in the reactant side of the reaction has switched from Na+ to Al 3+ in the product side. Decomposition is where a compound from the reactant side of the reaction would dissolve into elements in the product side, but that's not the case in this example.

If you were to have a bottle containing compound X in your closet, what phase would it most likely be in? *

Answers

Answer:

Most likely gas

Explanation:

Which is an example of a three
dimensional measurement of
volume?
A. 120 cubic meters
B. 120 grams
C. 120 miles per hour
D. 120 units

Answers

Answer:

It's A. 120 cubic meters

It’s a.120 cubic meters

Which isotope of iron from the periodic table is most abundant

Answers

Answer:

Iron has four naturally-occurring stable isotopes, 54Fe, 56Fe, 57Fe and 58Fe. The relative abundances of the Fe isotopes in nature are approximately 54Fe (5.8%), 56Fe (91.7%), 57Fe (2.2%) and 58Fe (0.3%).

Which direction does heat flow from

Answers

And unless people interfere, thermal energy — or heat — naturally flows in one direction only: from hot toward cold. Heat moves naturally by any of three means. The processes are known as conduction, convection and radiation. Sometimes more than one may occur at the same time

Answer:

A

Explanation:

hot to cold; jus took the quiz;)

Who developed the gas law that relates pressure and temperature?

Answers

Explanation:

physicist Robert Boyle

Answer: Boyle

Explanation: Educere Answer

You got out to dinner and the bills comes to $44.79. How much should you tip if you want the tip to be 18.0% of the bill?

Answers

Answer:

7%

Explanation:

I'd you have $44.79 you put the decimal next to the first 4 so 10% would be $4 and 20% would be $8 so 18% will be like 7

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