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3 years ago

What five elements make up 99% of living things

Chemistry

1 answer:

MA_775_DIABLO [31]3 years ago

4 0

Answer:

oxygen, carbon, hydrogen, nitrogen, and sulfur

Explanation:

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What is the number assigned to an element on the Periodic Table?

spayn [35]

Answer:

Element Atomic Number One number you will find on all periodic tables is the atomic number for each element.

Explanation:

<em>hope it helps :))</em>

6 0

3 years ago

A volume of 80.0 mL of H2O is initially at room temperature (22.00 ∘C). A chilled steel rod at 2.00 ∘C is placed in the water. I

murzikaleks [220]

Answer:

The mass of the steel bar is 26.833 grams

Explanation:

<u>Step 1: </u>data given

ΣQ gained = ΣQ lost

Q=m*C*ΔT

with m = mass in grams

with C= specific heat capacity ( in J/(g°C))

with ΔT = change in temperature = T2-T1

Qsteel = Qwater

msteel * Csteel * (T2steel - T1steel) = mwater * Cwater * (T2water - T1water)

Mass of steel = TO BE DETERMINED

mass of water =⇒ since 1mL = 1g : 80 mL = 80g

Csteel =0.452 J/(g °C

Cwater = 4.18 J/(g °C

initial temperature steel T1 : 2 °C

final temperature steel T2 = 21.3 °C

initial temperature water T1 =22 °C

final temperature water T2 = 21.3 °C

<u>Step 2:</u> Calculate mass of steel

msteel * Csteel * (T2steel - T1steel) = mwater * Cwater * (T2water - T1water)

msteel * 0.452 *(21.3-2) = 80 * 4.18 * (21.3-22)

msteel = (80 * 4.18 * (-0.7)) / (0.452 * 19.3)

msteel = -234.08 / 8.7236

msteel = -26.833 g

Since mass can't be negative we should take the absolute value of it = 26.833g

The mass of the steel bar is 26.833 grams

6 0

3 years ago

Question - Complete and balance the following chemical equations:

Mekhanik [1.2K]

Answer is because
Please give feedback

6 0

2 years ago

The following reaction shows calcium chloride reacting with silver nitrate.

adell [148]

Grams of Ca(NO₃)₂ produced : 0.985 g

<h3>Further explanation</h3>

A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.

Reaction

CaCl₂ + 2AgNO₃ → 2AgCl + Ca(NO₃)₂

MW AgNO₃ : 107.9+14+3.16=169.9

mol AgNO₃ :

$\tt \dfrac{2}{169.9}=0.012$

mol ratio Ca(NO₃)₂ : AgNO₃ = 1 : 2, so mol Ca(NO₃)₂ :

$\tt \dfrac{1}{2}\times 0.012=0.006$

MW Ca(NO₃)₂ : 40.1+2.14+6.16=164.1 g/mol

mass Ca(NO₃)₂ :

$\tt 0.006\times 164.1=0.985$

7 0

3 years ago

. Which type of energy is involved in the operation of simple machines?

quester [9]

Input an output energy

4 0

3 years ago