Select the two chemical reactions that adhere to the law of conservation of matter.

Which of the following is not a part of every scientific investigation?

Dmitry_Shevchenko [17]

Answer:

the correct answer is Group of answer choices

6 0

3 years ago

How can you identify gas in a chemical reaction without observing the atoms or molecules?

nikitadnepr [17]

Answer:

There are five signs of a chemical change:

Colour Change.

Production of an odour.

Change of Temperature.

Evolution of a gas (formation of bubbles)

Precipitate (formation of a solid).

5 0

2 years ago

The direction of electrical force is based on the fact that like charges will___each other.

NeTakaya

Answer:

repel

Explanation:

When it comes to electrical forces, "opposites charges attract" while "like charges repel."

There are primarily two types of charges: positive charge and negative charge. The forces they exert upon each other will depend on their charges. The positive charge has an attractive force to a negative charge. On the contrary, it has a repulsive force to the same positive charge. Thus, it will repel each other.

So this means that opposite charges will draw closer together while like charges will move apart from each other.

7 0

3 years ago

In which of the following sets are the charges given correctly for all the

Ronch [10]

Answer:

B) K⁺, Sr²⁺ , O²⁻

Explanation:

Potassium is present in group one. It is alkali metal and have one valance electron.Potassium need to lose its one valance electron and form cation to get complete octet.

That's why it shows K⁺.

Sr is alkaline earth metal. It is present in group two. It has two valance electrons. Strontium needed to lose its two valance electrons and get stable electronic configuration.

When it loses its two valance electrons it shows cation with charge of +2.

Sr²⁺

Oxygen is present in group 16. It has sex valance electrons. It needed two more electrons to complete the octet. That's why oxygen gain two electron and form anion with a charge of -2.

O²⁻

3 0

3 years ago

A 112 gram sample of an unknown metal was heated from 0.0C to 20.0C. The sample absorbed 1004 J of energy. What was the specific

worty [1.4K]

Answer:

The specific heat of the sample unknown metal is approximately 0.45 J/g °C.

General Formulas and Concepts:
Thermodynamics

Specific Heat Formula: $\displaystyle q = mc \triangle T$

m is mass (g)
c is specific heat capacity (J/g °C)
ΔT is the change in temperature

Explanation:

Step 1: Define

Identify variables.

m = 112 g

ΔT = 20.0 °C

q = 1004 J

Step 2: Solve for c

Substitute in variables [Specific Heat Formula]: $\displaystyle 1004 \ \text{J} = (112 \ \text{g})(c)(20.0 \ ^{\circ} \text{C})$
Simplify: $\displaystyle 1004 \ \text{J} = (2240 \ \text{g} \ ^\circ \text{C})c$
Isolate c: $\displaystyle c = 0.448214 \ \text{J} / \text{g} \ ^\circ \text{C}$
Round [Sig Figs]: $\displaystyle c \approx 0.45 \ \text{J} / \text{g} \ ^\circ \text{C}$

∴ specific heat capacity c is equal to around 0.45 J/g °C.

---

Topic: AP Chemistry

Unit: Thermodynamics

5 0

3 years ago